Journal articles: 'Magnetization'

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Bolletta, Juan P., François Fauth, Christine Martin, and Antoine Maignan. "Magnetization reversal tuning in honeycomb ferrimagnet Ni₄Nb₂O₉." Journal of Applied Physics 132, no. 15 (October 21, 2022): 153901. http://dx.doi.org/10.1063/5.0107661.

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Ni4Nb2O9 displays magnetization reversal, a particular behavior in which magnetization opposes an applied magnetic field. Previous studies have shown that this is caused by the antiferromagnetic coupling of two different layers of ferromagnetic Ni cations. In this work, magnetization reversal is controlled by the substitution of Ni by non-magnetic Zn. Ni4− xZn xNb2O9 materials with x = 0.25, 0.50, and 0.75 maintain the orthorhombic Ni4Nb2O9-type structure but display counterintuitive changes in the magnetic properties including increases in low-temperature net magnetizations, remnant magnetizations, and compensation temperatures. Furthermore, the magnetization reversal is significantly enhanced for x = 0.50 while supressed for x = 0.75, underscoring the strong effects of Zn substitution.

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Tajik, F., N. Allameh, A. A. Masoudi, and G. Palasantzas. "Nonlinear actuation of micromechanical Casimir oscillators with topological insulator materials toward chaotic motion: Sensitivity on magnetization and dielectric properties." Chaos: An Interdisciplinary Journal of Nonlinear Science 32, no. 9 (September 2022): 093149. http://dx.doi.org/10.1063/5.0100542.

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We have investigated the dynamical actuation of micro-electromechanical systems under the influence of attractive and repulsive Casimir forces between topological insulator plates as a function of their dielectric function and coating magnetization. The analysis of the Casimir force in the limit of strong and weak magnetization shows that the attractive force, which is produced for plate magnetizations in the same direction, is greater than the repulsive force that is produced for opposite magnetizations. However, both forces remain comparable for intermediate magnetizations. Moreover, for weak magnetization, the attractive force becomes stronger for an increasing dielectric function, while the opposite occurs for the repulsive force. On the other hand, increasing magnetization decreases the influence of the dielectric function on both the repulsive and attractive forces. Furthermore, for conservative systems, bifurcation and phase portrait analysis revealed that increasing magnetization decreases the regime of stable operation for devices with attractive forces, while their operation remains always stable under the presence of repulsive forces. Finally, for non-conservative periodically driven systems, the Melnikov function and Poincaré portrait analysis show that for magnetizations in the same direction leading to strong attractive Casimir forces, chaotic motion toward stiction is highly likely to occur preventing the long-term prediction of actuating dynamics. A remedy for this situation is obtained by the application of any magnetization in opposite directions between the interacting surfaces since the repulsive force makes it possible to prevent stiction.

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Chen, Hui, Guo Ying Zhang, Dan Yang, Yi Feng Duan, and Hai Shun Liu. "A Study on Step-Like Magnetization Curves in Tb₃Ga₅O₁₂ at Low Temperature." Advanced Materials Research 415-417 (December 2011): 1315–18. http://dx.doi.org/10.4028/www.scientific.net/amr.415-417.1315.

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The low temperature magnetizations of TbGG have been systematically investigated from the average effect of the nonequivalent crystal sites. Our calculated results show that the different nonequivalent crystal sites have the different contributions to the magnetization. The step-like appearance of the low temperature magnetization curves in TbGG originates from the average effect of the magnetizations of six nonequivalent crystal sites, not from the near-crossing of the lowest energy levels of Tb3+ions.

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Бахметьев, М. В., М. В. Бурканов, Р. А. Валеев, В. П. Пискорский, and Р. Б. Моргунов. "Переориентация намагниченности гетероструктур GdFeCo/Ir/GdFeCo при критических температурах." Физика твердого тела 65, no. 5 (2023): 790. http://dx.doi.org/10.21883/ftt.2023.05.55496.26.

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In GdFeCo/Ir/GdFeCo heterostructures with amorphous GdFeCo layers, three critical points were found in the temperature dependences of the magnetization. In the neighborhood of 100 K, the temperature of compensation for the magnetizations of the Gd and FeCo sublattices is observed, which is found in the form of a magnetization minimum and does not depend on the magnetic field. As the temperature decreases, a sharp stepwise transition is observed, which corresponds to the switching of the mutual magnetization’s orientation of the GdFeCo layers between their parallel and antiparallel configurations. This transition depends on the magnetic field in which the measurement is made. Its critical temperature shifts in the range of 70–300 K with a change in the field in the range of 0.5–5 T. At low temperatures < 50 K, a transition to the spin glass state is observed, which is accompanied by a decrease in the magnetic moment to zero and disappears when the field is applied.

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Bakhmetiev M. V., Burkanov M.V., Valeev R.A., Piskorskii V.P., and Morgunov R.B. "Magnetization reorientation of GdFeCo/Ir/GdFeCo heterostructures at critical temperatures." Physics of the Solid State 65, no. 5 (2023): 759. http://dx.doi.org/10.21883/pss.2023.05.56047.26.

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In GdFeCo/Ir/GdFeCo heterostructures with amorphous GdFeCo layers, three critical points were found in the temperature dependences of the magnetization. In the neighborhood of 100 K, the temperature of compensation for the magnetizations of the Gd and FeCo sublattices is observed, which is found in the form of a magnetization minimum and does not depend on the magnetic field. As the temperature decreases, a sharp stepwise transition is observed, which corresponds to the switching of the mutual magnetization's orientation of the GdFeCo layers between their parallel and antiparallel configurations. This transition depends on the magnetic field in which the measurement is made. Its critical temperature shifts in the range of 70-300 K with a change in the field in the range of 0.5-5 T. At low temperatures <50 K, a transition to the spin glass state is observed, which is accompanied by a decrease in the magnetic moment to zero and disappears when the field is applied. Keywords: Compensation temperature, synthetic ferrimagnet, exchange interaction, magnetic anisotropy.

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Sakai, Tôru, Hiroki Nakano, Rito Furuchi, and Kiyomi Okamoto. "Field-Induced Quantum Spin Nematic Liquid Phase in the S=1 Antiferromagnetic Heisenberg Chain with Additional Interactions." Journal of Physics: Conference Series 2164, no. 1 (March 1, 2022): 012030. http://dx.doi.org/10.1088/1742-6596/2164/1/012030.

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Abstract The magnetization process of the S = 1 antiferromagnetic chain with the single-ion anisotropy D and the biquadratic interaction is investigated using the numerical diagonalization. Both interactions stabilize the 2-magnon Tomonaga-Luttinger liquid (TLL) phase in the magnetization process. Based on several excitation gaps calculated by the numerical diagonalization, some phase diagrams of the magnetization process are presented. These phase diagrams reveal that the spin nematic dominant TLL phase appears at higher magnetizations for sufficiently large negative D.

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Baratchart, Laurent, Cristóbal Villalobos Guillén, and Douglas P. Hardin. "Inverse potential problems in divergence form for measures in the plane." ESAIM: Control, Optimisation and Calculus of Variations 27 (2021): 87. http://dx.doi.org/10.1051/cocv/2021082.

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We study inverse potential problems with source term the divergence of some unknown (ℝ3-valued) measure supported in a plane; e.g., inverse magnetization problems for thin plates. We investigate methods for recovering a magnetization μ by penalizing the measure-theoretic total variation norm ∥μ∥TV , and appealing to the decomposition of divergence-free measures in the plane as superpositions of unit tangent vector fields on rectifiable Jordan curves. In particular, we prove for magnetizations supported in a plane that TV -regularization schemes always have a unique minimizer, even in the presence of noise. It is further shown that TV -norm minimization (among magnetizations generating the same field) uniquely recovers planar magnetizations in the following two cases: (i) when the magnetization is carried by a collection of sufficiently separated line segments and a set that is purely 1-unrectifiable; (ii) when a superset of the support is tree-like. We note that such magnetizations can be recovered via TV -regularization schemes in the zero noise limit by taking the regularization parameter to zero. This suggests definitions of sparsity in the present infinite dimensional context, that generate results akin to compressed sensing.

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Kotzer, T. G., T. K. Kyser, and E. Irving. "Paleomagnetism and the evolution of fluids in the Proterozoic Athabasca Basin, northern Saskatchewan, Canada." Canadian Journal of Earth Sciences 29, no. 7 (July 1, 1992): 1474–91. http://dx.doi.org/10.1139/e92-118.

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In the Athabasca Basin, diagenetic hematite of variable paragenesis occurs throughout the sandstones and underlying paleoregolith. This hematite carries three distinct, single-component magnetizations: A (D = 158°, I = 62°, α95 = 5°, n = 21); B (D = 11°, I = −36°, α95 = 7°, n = 6); and C (D = 18°, I = 79°, α95 = 3°, n = 27). In some areas of the sandstones, such as near reactivated fault zones, the diagenetic hematite has been altered to goethite which yields a very low-intensity, incoherent D magnetization. Ages for the A, B, and C magnetizations, inferred from comparisons with paleomagnetic directions in Precambrian rocks whose ages are known approximately, are 1750–1600, 1600–1450, and about 900 Ma, respectively. The A magnetization is carried by the earliest formed hematite, and its estimated age compares well with U–Pb ages of 1650–1700 Ma for early diagenetic apatite. U–Pb and Rb–Sr ages of approximately 1500 and 900 Ma for uraninite and illite coeval with hematite that carries the B and C magnetizations compare well with their ages estimated from paleomagnetism. The development of B magnetization appears to be coeval with high-grade, unconformity-type uranium mineralization.Petrographic and field relationships indicate that the A magnetization is carried by hematite formed during initial diagenesis of the Athabasca sandstones, the B magnetization is carried by hematite formed during peak diagenesis, and the C magnetization is carried by hematite formed during subsequent high-temperature hydrothermal alteration. The incoherent D magnetizations have resulted from degradation of hematite to goethite as a result of incursion of low-temperature meteoric waters along fault zones that have been continuously reactivated since the late Precambrian. δ18O values of clay minerals and of the coeval hematite which carries the B and C magnetization indicate that they were formed from a fluid having temperatures of 150–200 °C and δ18O values near 1.0‰. Fluids that deposited the early formed hematite carrying the A magnetism are relatively 18O depleted, with values of approximately 0.8‰ and somewhat lower temperatures of 120–160 °C. Intermingling of A, B, and C magnetizations indicates either that hematite may be deposited by one fluid and reprecipitated by a subsequent fluid, or that fluid flow was controlled by local variations in permeability. Evidently, fluid flow has been episodic and basin wide and has occurred over a time span on the order of 108 years. It is suggested that the stratigraphy of the sandstones controlled the basin-wide lateral migration of the basinal fluids and that faults facilitated interformational fluid flow.

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Mahdiuon-Rad, S., S. R. Mousavi-Aghdam, M. Reza Feyzi, and M. B. B. Sharifian. "Analysis of PM Magnetization Field Effects on the Unbalanced Magnetic Forces due to Rotor Eccentricity in BLDC Motors." Engineering, Technology & Applied Science Research 3, no. 4 (August 11, 2013): 461–66. http://dx.doi.org/10.48084/etasr.296.

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This paper investigates both static and dynamic eccentricities in single phase brushless DC (BLDC) motors and analyzes the effect of the PM magnetization field on unbalanced magnetic forces acting on the rotor. Three common types of PM magnetization field patterns including radial, parallel and sinusoidal magnetizations are considered. In both static and dynamic eccentricities, harmonic components of the unbalanced magnetic forces on the rotor are extracted and analyzed. Based on simulation results, the magnetization fields that produce the lowest and highest unbalanced magnetic forces are determined in rotor eccentricity conditions.

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Pedersen, L. B. "Relations between potential fields and some equivalent sources." GEOPHYSICS 56, no. 7 (July 1991): 961–71. http://dx.doi.org/10.1190/1.1443129.

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The concept of equivalent sources is described from first principles. Two types of sources that produce the same magnetic field are studied in detail: thin sheets and uniaxially magnetized half‐spaces. Simple analytic solutions show that their magnetization variations are essentially given by the pseudogravity field and the magnetic field, respectively. While the former varies slowly to account for the slow variation in the vertically integrated magnetization, the latter varies rapidly to account for the spatial variation in rock magnetization close to the observation points. An extension of these simple distributions is the sandwich distribution. Using statistical arguments, we construct sandwich distributions. The depths and mean magnetizations of each layer are found from the decay of the azimuthally averaged power spectrum. The equivalent layer magnetizations closely resemble the magnetic field anomaly when upward‐continued to a height equal to the mean depth of the layer.

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Marenkin, S. F., V. M. Novotortsev, I. V. Fedorchenko, S. A. Varnavskiy, L. A. Koroleva, D. M. Zashchirinskii, T. M. Khapaeva, et al. "Novel Ferromagnetic Mn-Doped ZnSiAs₂ Chalcopyrite with Curie Point Exceeded Room Temperature." Solid State Phenomena 152-153 (April 2009): 311–14. http://dx.doi.org/10.4028/www.scientific.net/ssp.152-153.311.

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Based on Mn-doped chalcopyrite ZnSiAs2 the new dilute magnetic semiconductor with p-type conductivity was produced. The Curie temperature behavior of the produced semiconductor is distinctly dependent on the Mn concentration: 325 K for 1 wt.% and 337 K for 2 wt.% of Mn, consequently. Magnetization, electrical resistance, magnetic resistance and Hall effect of mentioned compositions were studied. Temperature dependence of magnetization M(T) have complicate behavior. For T  15 K the M(T) dependence is characteristic for superparamagnetic and at T > 15 K magnetization is sum of magnetizations of ensemble of superparamagnetic clusters and ferromagnetic phase contained frustration regions.

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Коплак, O. В., Е. В. Дворецкая, А. Д. Таланцев, Д. В. Королев, Р. А. Валеев, В. П. Пискорский, А. С. Денисова, and Р. Б. Моргунов. "Ориентационная зависимость магнитного момента микропроводов alpha-Fe(PrDy)(CoFeB)." Физика твердого тела 62, no. 4 (2020): 562. http://dx.doi.org/10.21883/ftt.2020.04.49121.649.

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The anisotropy of magnetization of α-Fe/(PrDy)(FeCo) core-shell microwires was studied at 300 K. The magnetization component of the α-Fe core directed along microwire axis and non-collinearly directed component of the microwire shell with correspondent saturation fields~ 100 Oe and > 10 kOe were separated. The directions of magnetizations of the shell and core of the microwire are differ by 170 grad.

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Zhou, Qiong, Yin Chun Hu, Yu Liang Ma, and Yong Ji Weng. "The Influence of Water Content on the Morphology and Magnetic Properties of Nickel Nanoparticles Prepared in Reverse Microemulsion." Advanced Materials Research 287-290 (July 2011): 494–98. http://dx.doi.org/10.4028/www.scientific.net/amr.287-290.494.

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Magnetic nickel nanoparticles are prepared by NaBH4reducing agent in AOT reverse microemulsion, the influence of water content on the morphology and magnetic properties of nickel nanoparticles are investigated by TEM study, size distribution, XRD characterization and magnetization curves. The results show that spherical and polydispered particles are obtained in microemulsion. The dimension and polydispersity of particles increased with the increasing of water content. Magnetization curves clearly indicate a ferromagnetic behavior with high coercivity values. At water content of W0=41.7, the product has a high saturated magnetization 70.68 emu/g with its residual magnetizations 28.02 emu/g, higher than the sample obtained at water content of W0=13.9.

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KIM, SOO KYUNG, DONGSHENG LI, MOE A. KHALEEL, KIM F. FERRIS, and HAMID GARMESTANI. "THERMOMAGNETIC PROPERTIES OF RARE-EARTH REPLACEMENT CRITICAL MAGNETIC MATERIALS FROM DFT CALCULATION: MnBi AND MnSb." International Journal of Computational Materials Science and Engineering 01, no. 04 (December 2012): 1250036. http://dx.doi.org/10.1142/s2047684112500364.

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MnBi has gained much attention as a replacement for critical rare earth magnetic material not only due to its strong magnetization and coercive power, but also because of its capability to retain magnetization at elevated temperatures while most other compounds decline. To investigate the origin of this temperature dependence, we have performed a series of first principles electronic structure calculations on the thermomagnetic properties of MnBi and compared it with MnSb , another ferromagnetic material with a strong magnetic energy product, same crystal structure at room temperature and similar Curie temperature. Three structural phases were considered in this study: NiAs -type ( B81 ), MnP -type ( B31 ) and a zincblende-type ( B3 ) structures. Calculated magnetizations demonstrated structural effects on temperature dependent magnetization. For the same NiAs -type structure, MnBi has a monotonic increase in magnetization with increasing temperature while MnSb decreases. In the other two structures, magnetization in MnBi and MnSb are much less sensitive to temperature. Results from this study suggest a structural design rule for the development of new MnBi related materials.

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Vlasov, V. S., V. G. Shavrov, and V. I. Shcheglov. "Orientational Transition of Magnetization Under Conditions." Радиотехника и электроника 68, no. 1 (January 1, 2023): 69–74. http://dx.doi.org/10.31857/s0033849423010138.

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The effect of high-order uniaxial anisotropy on the nature of orientational transition of magnetizationis considered. In the geometry of normal magnetization of the medium with respect to the anisotropy axis, the energy density and the equilibrium position of magnetization are obtained depending on the magnitude of the applied field. The orientation of magnetization is considered for anisotropy from the second to the eighth even orders only. As an example, the simultaneous presence of anisotropy of the second and fourthorders is considered. For this case, an algebraic equation of the third degree is obtained for the analysis of which the Cardano discriminant is used. It is shown that in the case of a negative value of the discriminant, the dependence of the magnetization orientation on the field has a hysteresis character.

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ZHANG, L., G. LIU, X. LENG, X. B. XU, S. Y. DING, Y. L. JIAO, and L. XIAO. "MAGNETIZATION OF Ag-Y1.8Ba2.4Cu3.4O7-x." International Journal of Modern Physics B 19, no. 01n03 (January 30, 2005): 311–13. http://dx.doi.org/10.1142/s0217979205028475.

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Three MTG Ag-Y1.8Ba2.4Cu3.4O7-x samples were fabricated to study the effect of doping Ag on magnetization. Magnetizations measured at various temperatures and fields show two peaks for all samples: the first peak in low field and second peak in middle field. We examined the effect of doping Ag and temperature on these peaks and discussed the origin of the peaks.

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Shi, Xiaoqing, Hua Geng, and Shuang Liu. "Magnetization Vector Inversion Based on Amplitude and Gradient Constraints." Remote Sensing 14, no. 21 (October 31, 2022): 5497. http://dx.doi.org/10.3390/rs14215497.

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Magnetization vector inversion has been developed since it can increase inversion accuracy due to the unknown magnetization direction caused by remanence. However, the three components of total magnetizations vector are simultaneously inverted and then synthesized into the magnetization magnitude and direction, which increases the inherent non-uniqueness of the inversion. The positions of the three components of the magnetization vector are originally consistent. If there is a lack of constraints between them during the inversion process, they may be misaligned, resulting in a large deviation between the synthesized vector model and the ground truth. To address this issue and at the same time increase the accuracy of the edges of the inversion models, this paper proposes a magnetization vector inversion scheme with model and its gradients’ constraints by sparse Lp norm functions based on the amplitude of the three components of the magnetization vector instead of a single component to improve the accuracy of the inversion result. To evaluate the inversion accuracy performance, an improved evaluation index is also proposed in this paper, which can better evaluate the accuracy of the shape, position and magnetization amplitude of the inversion model. The proposed inversion method can recover the models with higher accuracy compared with traditional methods, indicated by the inverted model and the evaluation indexes. Simulation results based on the open-source SimPEG software and inversion on actual measured Galinge iron ore deposit (China) data verified the effectiveness and advantages of the proposed method.

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Morris, W. A. "Paleomagnetism of Carboniferous strata from the Stellarton Gap." Canadian Journal of Earth Sciences 39, no. 10 (October 1, 2002): 1527–40. http://dx.doi.org/10.1139/e02-055.

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Deposition of Carboniferous sediments within the Stellarton Graben of Nova Scotia was controlled by displacements on the bounding Hollow and Cobequid fault systems. Periods of both normal and transcurrent faulting have occurred on both faults. As a result, models for the development of the Stellarton Basin have included a pull-apart basin and a thermal subsidence basin. Paleomagnetic study of stratigraphic sequences from within the graben showed evidence for three separate periods of remanence acquisition (ST3 ST2 ST1). Ordering the acquisition sequence for these three magnetizations is mainly circumstantial, being based on the distribution of each remanence phase relative to stratigraphic position and deformation of the strata. The oldest magnetization ST3 is grossly divergent from previously reported Carboniferous results suggesting an early period of large-scale clockwise rotation. Magnetization ST2 has a similar pole position to many others from Maritime Carboniferous basins located within the Appalachian orogenic belt. The divergence of these poles from the cratonic poles is interpreted as indicating that these magnetizations were acquired at a time when the reference horizontal was different to the present horizontal. The third magnetization ST3 is identical to a large number of late-stage Carboniferous regional overprint magnetizations. In summary, the paleomagnetic evidence suggests that the Stellarton Basin was formed in an early (Westphalian B to C) pull-apart phase that was followed by a later thermal subsidence phase.

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Nell, Martin Marco, Benedikt Schauerte, Tim Brimmers, and Kay Hameyer. "Simulation of iron losses in induction machines using an iron loss model for rotating magnetization loci in no electrical steel." COMPEL - The international journal for computation and mathematics in electrical and electronic engineering 41, no. 2 (January 5, 2022): 600–614. http://dx.doi.org/10.1108/compel-06-2021-0220.

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Purpose Various iron loss models can be used for the simulation of electrical machines. In particular, the effect of rotating magnetic flux density at certain geometric locations in a machine is often neglected by conventional iron loss models. The purpose of this paper is to compare the adapted IEM loss model for rotational magnetization that is developed within the context of this work with other existing models in the framework of a finite element simulation of an exemplary induction machine. Design/methodology/approach In this paper, an adapted IEM loss model for rotational magnetization, developed within the context of the paper, is implemented in a finite element method simulation and used to calculate the iron losses of an exemplary induction machine. The resulting iron losses are compared with the iron losses simulated using three other already existing iron loss models that do not consider the effects of rotational flux densities. The used iron loss models are the modified Bertotti model, the IEM-5 parameter model and a dynamic core loss model. For the analysis, different operating points and different locations within the machine are examined, leading to the analysis of different shapes and amplitudes of the flux density curves. Findings The modified Bertotti model, the IEM-5 parameter model and the dynamic core loss model underestimate the hysteresis and excess losses in locations of rotational magnetizations and low-flux densities, while they overestimate the losses for rotational magnetization and high-flux densities. The error is reduced by the adapted IEM loss model for rotational magnetization. Furthermore, it is shown that the dynamic core loss model results in significant higher hysteresis losses for magnetizations with a high amount of harmonics. Originality/value The simulation results show that the adapted IEM loss model for rotational magnetization provides very similar results to existing iron loss models in the case of unidirectional magnetization. Furthermore, it is able to reproduce the effects of rotational flux densities on iron losses within a machine simulation.

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Silva, João B., Suzan S. Vasconcelos, and Valeria C. Barbosa. "Apparent-magnetization mapping using entropic regularization." GEOPHYSICS 75, no. 2 (March 2010): L39—L50. http://dx.doi.org/10.1190/1.3358160.

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A new apparent-magnetization mapping method on the horizontal plane combines minimization of first-order entropy with maximization of zeroth-order entropy of the estimated magnetization. The interpretation model is a grid of vertical, juxtaposed prisms in both horizontal directions. To estimate the magnetization of the prisms, assume that the top and bottom of the magnetic sources are horizontal. Minimization of the first-order entropy favors solutions with sharp borders, and the maximization of zeroth-order entropy prevents the tendency of the estimated source to become a single prism with large magnetization. Thus, a judicious combination of both constraints can lead to solutions characterized by regions with virtually constant magnetizations separated by sharp discontinuities. This is applied to synthetic data from simulated intrusive bodies in sediments that have horizontal tops. By comparing the results with those obtained with the common Tikhonov regularization (smoothness constraint) method, it is shown that both methods produce good and equivalent locations of the central positions of the sources. However, entropic regularization delineates the boundaries of the bodies with greater detail. Both the proposed and the smoothness constraints are applied to real anomaly data over a magnetic skarn in Butte Valley, Nevada, U.S.A. Entropic regularization produced an estimated magnetization distribution with sharper boundaries, smaller volume, and higher apparent magnetization as compared with results produced by incorporating the smoothness constraint.

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Pedersen, Laust B., and Mehrdad Bastani. "Estimating rock-vector magnetization from coincident measurements of magnetic field and gravity gradient tensor." GEOPHYSICS 81, no. 3 (May 2016): B55—B64. http://dx.doi.org/10.1190/geo2015-0100.1.

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Poisson’s theorem relating components of the magnetic field to components of the gradient of the gravity vector assuming a common source has been cast into a general form. A given magnetization distribution in the terrain or in the underlying crust is propagated into the corresponding magnetic field through the gravity gradient tensor. Conversely, measured magnetic field anomalies and measured gravity gradient tensor anomalies can be used to estimate the unknown magnetization vectors without knowledge of the geometry of the sources. We have tested the method on recently acquired data over a greenstone belt in Northern Sweden. The topographic relief was sufficiently variable to dominate the measured gravity gradient tensor. In practice, we have concentrated on areas where the norm of the gravity gradient tensor reached a maximum so that there was a better chance of identifying isolated sources with well-defined density and magnetization. We have surrounded the selected points by a small window and used all the data lying within that window to estimate the magnetization vectors. We have compared the estimated amplitudes and directions of magnetization with those measured from selected rock samples in the area and found a relatively modest agreement. We have interpreted this as a result of two effects: (1) Measured magnetizations are generally lower than those estimated by this method, and we believe that this is related to the fact that the collection of samples in the field is biased because of a small number of outcrops in most parts of the area. (2) This analysis is biased toward high-amplitude magnetic anomalies; i.e., the estimation procedure works best for high-amplitude magnetic anomalies, in which case, the influence of neighboring anomalies is reduced. The estimated magnetization directions show a strong dominance of remanent magnetization over induced magnetization in agreement with laboratory measurements on rock samples from the area.

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Stauffer, D. "Monte Carlo Investigation of Rare Magnetization Fluctuations in Ising Models." International Journal of Modern Physics C 09, no. 04 (June 1998): 625–31. http://dx.doi.org/10.1142/s0129183198000510.

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For square and simple cubic Ising models at T=Tc, we look at the tails of the magnetization distribution for untypically large magnetizations. No indications for a stretched exponential or power law behavior are found.

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Chatterjee, Subham, S. Giri, S. K. De, and S. Majumdar. "Magnetic Investigations on Ni-Mn-Sn Ferromagnetic Shape Memory Alloy." Advanced Materials Research 52 (June 2008): 215–20. http://dx.doi.org/10.4028/www.scientific.net/amr.52.215.

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Ferromagnetic shape memory alloy of nominal composition Ni50Mn35Sn15 has been investigated by magnetic and transport measurements. Clear signature of first order martensitic transition is observed over a region around 180 K in resistivity, dc magnetization and ac susceptibility data. Field-cooled and zero-field-cooled magnetizations diverge below the martensitic transition, signifying magneto-thermal irreversibility originating from pinning by variants. The sample shows large negative magneto-resistance (-25% at 90 kOe) in the region of martensitic transition, which was found to be highly irreversible. A clear correspondence between magnetoresistance and dc magnetization is observed above the field of technical saturation.

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Rivkin, Kirill, and Michael Montemorra. "Spin wave computing using pre-recorded magnetization patterns." Journal of Applied Physics 132, no. 15 (October 21, 2022): 153902. http://dx.doi.org/10.1063/5.0096192.

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We propose a novel type of spin wave computing device, based on a bilayer structure that includes a “bias layer” made from a hard magnetic material and a “propagation layer” made from a magnetic material with low damping, for example, yttrium garnet or permalloy. The bias layer maintains a stable pre-recorded magnetization pattern, which generates a bias field with a desired spatial dependence, which in turn sets the equilibrium magnetization inside the propagation layer. When an external source applies an RF field to the propagation layer, excited spin waves scatter on the magnetization's inhomogeneities resulting in complex interference behavior. This scattering interference can be utilized to perform a variety of mathematical operations including Vector-Matrix multiplication. The spatial dependence of such magnetization patterns can be estimated via perturbation theory.

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Silveyra, Josefina María, and Juan Manuel Conde Garrido. "On the anhysteretic magnetization of soft magnetic materials." AIP Advances 12, no. 3 (March 1, 2022): 035019. http://dx.doi.org/10.1063/9.0000328.

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Electrical steels are still the materials of choice for large-scale transformers and most electric motors. Yet, they may present a nonhomogeneous magnetic nature which prevents describing accurately their anhysteretic magnetization with the Langevin-Weiss model. Although interpolation and extrapolation methods may be used to model any anhysteretic curve, a simple and physically-based model would be of great value for fundamental and applied research. Inspired in the law of partial volumes for gas mixtures, we proposed a law of partial magnetizations for magnetic mixtures. In a two-component system, the model leads to the double Langevin-Weiss function. We also introduced a graphical method and a fitting approach to analyze and model anhysteretic magnetization curves. A semi-log magnetization derivative plot is central to this end. We validated our strategy through well-motivated examples using published data on soft magnets. The single Langevin-Weiss function provided an accurate description of the magnetization of isotropic and anisotropic magnetically homogeneous materials: a soft ferrite and a nanocrystalline alloy, respectively. For modelling a magnetization transverse to the material’s preferred direction, the key is to allow a negative molecular field constant. The double Langevin-Weiss function was suitable for less homogeneous materials, such as a grain-oriented electrical steel magnetized along the rolling direction and a non-oriented electrical steel. Moreover, a highly-grain-oriented electrical steel magnetized transverse to the rolling direction, which exhibits a constricted hysteresis loop, could be modeled in excellent agreement with data. The key for the latter, has been to allow an antiparallel arrangement of the mean magnetization of both components.

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26

Koehler, G., T. K. Kyser, R. Enkin, and E. Irving. "Paleomagnetic and isotopic evidence for the diagenesis and alteration of evaporites in the Paleozoic Elk Point Basin, Saskatchewan, Canada." Canadian Journal of Earth Sciences 34, no. 12 (December 1, 1997): 1619–29. http://dx.doi.org/10.1139/e17-130.

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In the Paleozoic Elk Point Basin, Saskatchewan, Canada, hematite in evaporite rocks of the Middle Devonian Prairie Formation records two magnetizations that are very different from those expected when the evaporites were originally deposited. The first (X magnetization) corresponds to Cretaceous or Cenozoic paleofield directions and contains both normal and reversed polarities. The second (Y magnetization) appears to be a composite of Cretaceous–Cenozoic and late Paleozoic (Kiaman) reversed polarity directions. The X magnetization occurs in anomalous ores and is associated with fine-grained hematite occurring predominantly along grain boundaries. The Y magnetization occurs in normal ore and is associated with sylvite that has hematite both along grain boundaries and within sylvite crystals, the latter inferred to be of Kiaman age. K–Ar ages of the host sylvites are also composite, and are consistent with those inferred from paleomagnetic directions. Stable isotopic compositions of fluid inclusions in halite and the associated hematite in the Prairie Formation indicate that the hematite carrying the X magnetization formed at low temperature (about 60 °C) by fluids similar to those currently resident in overlying formations. The hematite carrying the inferred late Paleozoic magnetization was also formed at low temperatures by fluids having δD and δ18O values significantly lower than Paleozoic seawater. Paleomagnetic, petrographic, and isotopic data, and K–Ar ages indicate that evaporites in the Elk Point Basin have been affected by major fluid events that occurred during the late Paleozoic and Cretaceous–Cenozoic. These fluids are most probably related to brines mat have their origins within the basin, which were mobilized by major tectonic events.

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Arun, R., R. Gopal, V. K. Chandrasekar, and M. Lakshmanan. "Effect of interlayer exchange coupling in spin-torque nano oscillator." Journal of Applied Physics 132, no. 9 (September 7, 2022): 094301. http://dx.doi.org/10.1063/5.0095705.

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The dynamics of the magnetization of the free layer in a spin-torque nano oscillator (STNO) influenced by a noncollinear alignment between the magnetizations of the free and pinned layers due to an interlayer exchange coupling has been investigated theoretically. The orientations of the magnetization of the free layer with that of the pinned layer have been computed through the macrospin model and they are found to match well with experimental results. The bilinear and biquadratic coupling strengths make the current to switch the magnetization between two states or oscillate steadily. The expressions for the critical currents between which oscillations are possible and the critical bilinear coupling strength below which oscillations are not possible are derived. The frequency of the oscillations is shown to be tuned and increased to or above 300 GHz by the current, which is the largest to date among nanopillar-shaped STNOs.

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Pilkington, Mark, and Majid Beiki. "Mitigating remanent magnetization effects in magnetic data using the normalized source strength." GEOPHYSICS 78, no. 3 (May 1, 2013): J25—J32. http://dx.doi.org/10.1190/geo2012-0225.1.

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We have developed an approach for the interpretation of magnetic field data that can be used when measured anomalies are affected by significant remanent magnetization components. The method deals with remanent effects by using the normalized source strength (NSS), a quantity calculated from the eigenvectors of the magnetic gradient tensor. The NSS is minimally affected by the direction of remanent magnetization present and compares well with other transformations of the magnetic field that are used for the same purpose. It therefore offers a way of inverting magnetic data containing the effects of remanent magnetizations, particularly when these are unknown and are possibly varying within a given data set. We use a standard 3D inversion algorithm to invert NSS data from an area where varying remanence directions are apparent, resulting in a more reliable image of the subsurface magnetization distribution than possible using the observed magnetic field data directly.

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29

Kharel, Parashu, Bhubnesh Lama, Matthew Flesche, Zachary Mehlberg, Buddhi Lamsal, Shah Valloppilly, Yue Zhou, David J. Sellmyer, and Tula R. Paudel. "Modifying magnetic properties of MnBi with carbon: an experimental and theoretical study." Journal of Physics D: Applied Physics 55, no. 26 (April 8, 2022): 265003. http://dx.doi.org/10.1088/1361-6463/ac5fd2.

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Abstract MnBi and MnBi-based materials have been investigated as prospective rare-earth-free permanent magnets with moderate energy product. One of the main issues with MnBi synthesis is the presence of residual Bi in the sample which reduces the net magnetization. We have found that MnBi synthesized in the presence of carbon substantially reduces the amount of residual Bi, improving its saturation magnetization. We have synthesized Mn55Bi45 and Mn55Bi45C x samples using arc melting and high-vacuum annealing. The room temperature x-ray diffraction patterns indicate that both Mn55Bi45 and Mn55Bi45C x crystallize in the hexagonal NiAs-type structure. The Rietveld analysis of the x-ray patterns shows that the amount of residual Bi reduces from 16 wt.% for Mn55Bi45 to 5 wt.% for Mn55Bi45Cx. The high-field (3 T) magnetizations measured at room temperature are 61 emu g−1 and 66 emu g−1 for Mn55Bi45 and Mn55Bi45C x , respectively. To understand the role of C in enhancing the magnetization of MnBi, we carried out the first-principles calculations of both stoichiometric and nonstoichiometric MnBi alloys, which suggests that the increase of magnetization in Mn55Bi45C x may be due to the coating of MnBi grains with C.

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30

Talantsev, Artem D., Ekaterina I. Kunitsyna, and Roman B. Morgunov. "The effect of Dzyaloshinskii–Moriya interaction on direct and backward transition between magnetic states of Pt/Co/Ir/Co/Pr synthetic ferrimagnet." Image Journal of Advanced Materials and Technologies 6, no. 3 (2021): 167–78. http://dx.doi.org/10.17277/jamt.2021.03.pp.167-178.

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In this paper, we present the study of domain structure accompanying interstate transitions in Pt/Co/Ir/Co/Pr synthetic ferrimagnet (SF) of 1.1 nm thick and 0.6 – 1.0 nm thin ferromagnetic Co layers. Variation in the thickness of the thin layer causes noticeable changes in the domain structure and mechanism of magnetization reversal revealed by MOKE (Magneto-Optical Kerr Effect) technique. Magnetization reversal includes coherent rotation of magnetization of the ferromagnetic layers, generation of magnetic nuclei, spreading of domain walls (DW), and development of areas similar with strip domains, dependently on thickness of the thin layer. Inequivalence of the direct and backward transitions between magnetic states of SF with parallel and antiparallel magnetizations was observed in sample with thin layer thicknesses 0.8 nm and 1.0 nm. Asymmetry of the transition between these states is expressed in difference fluctuation fields and shapes of reversal magnetization nucleus contributing to the correspondent forward and backward transitions. We proposed simple model based on asymmetry of Dzyaloshinskii–Moriya interaction. This model explains competition between nucleation and domain wall propagation due to increase/decrease of the DW energy dependently on direction of the spin rotation into the DW in respect to external field.

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Прудников, В. В., П. В. Прудников, and П. Н. Маляренко. "Монте-Карло-исследование влияния начальных состояний и дефектов структуры на неравновесное критическое поведение трехмерной модели Изинга." Физика твердого тела 60, no. 6 (2018): 1086. http://dx.doi.org/10.21883/ftt.2018.06.45981.05m.

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AbstractThe effect of various initial magnetizations m _0 and structural defects the nonequilibrium critical behavior of the three-dimensional Ising model is numerically studied. Based on an analysis of the time dependence of the magnetization and the two-time dependence of the autocorrelation function and dynamic susceptibility, the significant effect of initial states on relaxation magnetizations and aging effects characterized by anomalous relaxation inhibition and correlation in the system with increasing waiting time was revealed. The fluctuation–dissipation theorem violation was studied, and the values of the limit fluctuation–dissipation ratio (FDR) are calculated. It is shown that two universality subclasses can be distinguished in the nonequilibrium critical behavior of the three-dimensional Ising model with random initial magnetization m _0 These subclasses correspond to the system evolution from the high-temperature ( m _0 = 0) and low-temperature ( m _0 = 1) initial states with limit FDRs characteristic of these states.

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32

Sahu, Sivabrata, Himanshu Sekhar Gouda, and G. C. Rout. "Effect of impurity doping on AFM magnetization in graphene: A tight-binding model approach." International Journal of Computational Materials Science and Engineering 06, no. 04 (December 2017): 1850001. http://dx.doi.org/10.1142/s204768411850001x.

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We report here a tight-binding theoretical study of anti-ferromagnetism in graphene taking electron hopping up to third nearest neighbors. The graphene on substrate introduces inequivalence in the two sublattices of the honeycomb lattice. The on-site Coulomb interactions at two sublattices of graphene are treated within mean-field approximation and the electron occupancies at two sublattices include spin moments in opposite directions giving rise to anti-ferromagnetism in graphene. The AFM sublattice magnetizations are calculated by using Zubarev’s Green’s function technique and computed self-consistently for different ranges of Coulomb potential, substrate-induced gap and impurity concentrations. It is observed that [Formula: see text]-site magnetization is suppressed by [Formula: see text]-site impurity concentration, while [Formula: see text]-site magnetization remains unaffected. Similar effect has been observed at [Formula: see text]-site when doped with pentavalent dopant, while [Formula: see text]-site magnetization remains unaffected. Furthermore, substrate-induced AFM gap has also been observed at different ranges of temperature.

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33

Yang, C. P., Y. Z. Wang, G. H. Wu, B. P. Hu, X. F. Han, Z. L. Jiang, C. L. Ma, and J. Zhu. "Comparison of the crystallographic and magnetic properties between Tb2Fe16.46Cr1.23 and Tb3(Fe,Cr)29 single crystals." Journal of Materials Research 14, no. 11 (November 1999): 4195–99. http://dx.doi.org/10.1557/jmr.1999.0568.

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A novel Tb3(Fe,Cr)29 single crystal, which has a monoclinic Nd3(Fe,Ti)29-type structure, is obtained using the Czochralski method by performing a proper heat treatment on the Tb2Fe16.46Cr1.23 crystal with a Th2Ni17-type structure. Thermomagnetic curves along the easy axis and magnetization curves along the easy and hard axes are presented for both crystals. The lattice parameters are a = 1.058 nm, b = 0.848 nm, c = 0.968 nm, α = γ = 90°, and β = 96.93° for the Tb3(Fe,Cr)29 single crystal. The Curie temperatures, saturation magnetizations, and magnetocrystalline anisotropy constants are compared between the Tb-2:17 and Tb-3:29 crystals. The magnetization behavior along the hard axis is quite different as a first-order magnetization process (FOMP) of type I for the Tb-2:17, but a FOMP of type II for the Tb-3:29 crystal is observed below room temperature. At low temperatures, magnetohistory effects are detected for both crystals.

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34

Liu, Ruihao, Li Cai, Teng Xu, Jiahao Liu, Yang Cheng, and Wanjun Jiang. "Anomalous Nernst effect in compensated ferrimagnetic Co_xGd_1-_x films." Applied Physics Letters 122, no. 2 (January 9, 2023): 022406. http://dx.doi.org/10.1063/5.0121156.

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The anomalous Nernst effect (ANE) is one of the most intriguing thermoelectric phenomena, which has attracted growing interest both for its underlying physics and potential applications. Typically, a large ANE response is observed in magnets with pronounced magnetizations or nontrivial Berry curvature. Here, we report a significant ANE signal in compensated ferrimagnetic Co xGd1- x amorphous films, which exhibit vanishingly small magnetization. In particular, we found that the polarity of ANE signal is dominated by the magnetization orientation of the transition metal Co sublattices, rather than the net magnetization of Co xGd1- x films. This observation is not expected from the conventional understandings of ANE but is analogous to the anomalous Hall effect in compensated ferrimagnets. The joint contribution from the Berry curvature and the scattering mechanisms near the Co-dominant Fermi surface could interpret the Co-dominant property of ANE. Our work may trigger a more comprehensive understanding of ANE and may be useful for building energy-harvesting devices by employing ANE in compensated ferrimagnets.

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35

Raymond, C. A., and J. L. LaBrecque. "Magnetization of the oceanic crust: Thermoremanent magnetization of chemical remanent magnetization?" Journal of Geophysical Research 92, B8 (1987): 8077. http://dx.doi.org/10.1029/jb092ib08p08077.

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Steenland, Nelson C. "On: “Determination of crustal interface topography from potential fields” by M. Pilkington and D. J. Crossley (GEOPHYSICS, 51, 1277–1284, June 1986) and “Inversion of aeromagnetic data for multilayered models” by M. Pilkington and D. J. Crossley (GEOPHYSICS, 51, 2250–2254, December 1986)." GEOPHYSICS 52, no. 10 (October 1987): 1436–37. http://dx.doi.org/10.1190/1.1442257.

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The introduction of the airborne magnetometer in the 1940s led to the largest flow of data in geophysical history. Vacquier (1951) recognized the need for a concomitant system of interpretation of these data and pioneered the utilization of a rejected category of anomalies, the intrabasement contrasts in magnetization, for the basis of the desired system. These anomalies had great acclaim in oil and gas exploration in the late 1920s, but they led to the total disrepute of magnetics when facsimiles to the coincidence of production and intrabasement magnetization at Hobbs, New Mexico, discovered in 1928, did not achieve the same relationship. But Vacquier recognized the omnipresence of these anomalies, the singularity of individual anomalies, and their source in thick bodies of relatively steep sides and induced magnetizations. These simple but powerful deductions were reached pragmatically. To repeat, anomalies were singular because they were quite separate from one another. Therefore, the sides of their causative bodies had to be quite steep. An anomaly must be attributed to one magnetization contrast because it was one anomaly, and that magnetization was induced because the ratios of their positive and negative components correlated with the inclination of the Earth’s main magnetic field. (All of this may be found in GSA Memoir 47, 1951.)

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37

Rykov, A. I., S. Tajima, and F. V. Kusmartsev. "New Features of the Freezing Vortex Matter in Single Crystals of YBa2Cu3O7-δ." International Journal of Modern Physics B 12, no. 29n31 (December 20, 1998): 3326–29. http://dx.doi.org/10.1142/s0217979298002568.

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We report on the new features observed in the magnetization of a high-T c superconductor at cooling through the first order transition. The single crystal of YB2Cu3O 7-δ cooled in the magnetic field H‖c at cooling (FCC) exhibits a multipolar magnetic moment which results from the summing up over the sample of both the negative (magnetization of the uncompressed vortex lattice) and the positive local magnetic moments. The positive local moments correspond to the enhanced density of the trapped flux lines exceeding locally that for the external magnetic field. At large fields (> 3T) below freezing temperature Tf, the dipolar contribution into the magnetic moment is fully reversible, in agreement with zero density of critical current. The magnetization of the field-cooled sample measured at warming (FCW) exhibit jumps at clearly larger temperature Tm(>Tf). The jump from zero to a finite value in the octupolar magnetizations [Formula: see text] occurs at the same temperatures Tf, Tm as the conventional jump in the field-cooled dipolar magnetization [Formula: see text] related to the vortex ordering entropy (ΔS < k B ). The high-pole magnetic moments are metastable and exhibit long sample-specific relaxation, quickest in a narrow temperature range at T<Tm close to Tm.

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38

Abtahi, Sayyed Mohammad, Laust Börsting Pedersen, Jochen Kamm, and Thomas Kalscheuer. "A new reference model for 3D inversion of airborne magnetic data in hilly terrain — A case study from northern Sweden." GEOPHYSICS 83, no. 1 (January 2018): B1—B12. http://dx.doi.org/10.1190/geo2016-0331.1.

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The inherent nonuniqueness in modeling magnetic data can be partly reduced by adding prior information, either as mathematical constructs or simply as bounds on magnetization obtained from laboratory measurements. If a good prior model can be used as a reference model, then the quality of estimated models through an inverse approach can be greatly improved. But even though data on magnetic properties of rocks might exist, their distribution may often be quite irregular on local and regional scales, so that it is difficult to define representative classes of rock types suitable for constraining geophysical models of magnetization. We have developed a new way of constructing a reference model that varies only laterally and is confined to the part of the terrain that lies above the lowest topography in the area. To obtain this model, several estimated 2D magnetization distributions were constructed by data inversion as a function of the iteration number. Then, a suitable 2D model of the magnetization in the topography was chosen as a starting point for constructing a 3D reference model by modifying it with a vertical decay such that its average source depth was the same for all horizontal positions. The average source depth of the reference model was chosen to satisfy the average source depth obtained from analyzing the radial power spectrum of the area studied. Finally, the measured magnetic data were inverted in three dimensions using the given reference model. For a selected reference model, shallow structures indicated a better overall correlation with large remanent magnetizations measured on rock samples from the area. Throughout the entire model, the direction of magnetization was allowed to vary freely. We found that the Euclidean norm of the estimated model was reduced compared with the case where the magnetization direction was fixed.

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39

Harlan, Steve S. "Paleomagnetism of Middle Proterozoic diabase sheets from central Arizona." Canadian Journal of Earth Sciences 30, no. 7 (July 1, 1993): 1415–26. http://dx.doi.org/10.1139/e93-122.

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Paleomagnetic results from 1090 Ma diabase sheets of the southwestern U.S.A. diabase province exposed in central Arizona yield two distinct remanent magnetizations (herein termed ADn and ADr), in accordance with the findings of previous investigations. Magnetization ADn is well-defined and has an in situ mean direction of D = 283.3°, I = 45.1° (k = 17.7, α95 = 8.7°, n = 17 independent observations). A mean pole, after correction of paleomagnetic site means for a net 5° clockwise rotation of the Colorado Plateau and transition zone, is located at 22.7°N, 179.3°E (K = 21.9, A95 = 7.8°). The second magnetization (ADr) gives an in situ mean direction of D = 161.1°, I = −87.5° (k = 22.2, α95 = 19.9°, n = 4 independent observations) with a poorly defined pole at 37.6°N, 247.6°E (K = 6.5, A95 = 38.9°). Rock magnetic and alternating field and thermal demagnetization characteristics indicate the ADn and ADr magnetizations are both carried by low-Ti titanomagnetite. Both magnetizations are interpreted to be primary thermoremanent magnetizations acquired during emplacement and cooling of the diabase sheets at about 1090 – 1100 Ma. Comparison of the ADn pole and published geochronologic data from the Arizona diabase with the well-dated normal polarity poles of the Keweenawan region indicates that mafic magmatism in the southwestern U.S.A. diabase province and in the midcontinent rift was essentially synchronous.

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Roy, Kuntal. "Ultra-Low-Energy Electric Field-Induced Magnetization Switching in Multiferroic Heterostructures." SPIN 06, no. 03 (September 2016): 1630001. http://dx.doi.org/10.1142/s2010324716300012.

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Electric field-induced magnetization switching in multiferroics is intriguing for both fundamental studies and potential technological applications. Here, we review the recent developments on electric field-induced magnetization switching in multiferroic heterostructures. Particularly, we study the dynamics of magnetization switching between the two stable states in a shape-anisotropic single-domain nanomagnet using stochastic Landau–Lifshitz–Gilbert (LLG) equation in the presence of thermal fluctuations. For magnetostrictive nanomagnets in strain-coupled multiferroic composites, such study of magnetization dynamics, contrary to steady-state scenario, revealed intriguing new phenomena on binary switching mechanism. While the traditional method of binary switching requires to tilt the potential profile to the desired state of switching, we show that no such tilting is necessary to switch successfully since the magnetization’s excursion out of magnet’s plane can generate a built-in asymmetry during switching. We also study the switching dynamics in multiferroic heterostructures having magnetoelectric coupling at the interface and magnetic exchange coupling that can facilitate to maintain the direction of switching with the polarity of the applied electric field. We calculate the performance metrics like switching delay and energy dissipation during switching while simulating LLG dynamics. The performance metrics turn out to be very encouraging for potential technological applications.

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41

Iwata, N., T. Kimura, T. Shigeoka, and Y. Hashimoto. "Sublattice magnetization and magnetization process in TbCu2." Journal of Magnetism and Magnetic Materials 70, no. 1-3 (December 1987): 279–81. http://dx.doi.org/10.1016/0304-8853(87)90439-2.

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42

Okwokwo, Oke I., Neil C. Mitchell, Wen Shi, I. C. F. Stewart, and A. Y. Izzeldin. "How have thick evaporites affected early seafloor spreading magnetic anomalies in the Central Red Sea?" Geophysical Journal International 229, no. 3 (January 21, 2022): 1550–66. http://dx.doi.org/10.1093/gji/ggac012.

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SUMMARY The axial region of the Central Red Sea has been shown to be floored by oceanic crust, but this leaves the low amplitudes of off-axis magnetic anomalies to be explained. Furthermore, if seafloor spreading occurred in the late Miocene, it is unclear how that occurred as widespread evaporites were being deposited then and may have covered the spreading centre. In this study, we derive crustal magnetization for a constant-thickness source layer within the uppermost basement by inverting aeromagnetic anomalies using basement depths derived from seismic reflection and gravity data. Peak-to-trough variations in magnetization away from the axis are found to be slightly less than half of those of normal oceanic crust, but not greatly diminished, and hence the magnetic anomalies are mostly reduced by the greater depth of basement, which is depressed by isostatic loading by the evaporites (kilometres in thickness in places). There is no relationship between seafloor spreading anomalies and the modern distribution of evaporites mapped out using multibeam sonar data; magnetizations are still significant even where the basement lies several kilometres under the evaporites. This suggests that magnetizations have not been more greatly affected by alteration under the evaporites than typically exposed oceanic crust. A prominent magnetization peak commonly occurs at 60–80 km from the axis on both tectonic plates, coinciding with a basement low suggested previously to mark the transition to continental crust closer to the coasts. We suggest an initial burst of volcanism occurred at Chron 5 (at ∼10 Ma) to produce this feature. Furthermore, an abrupt change is found at ∼5 Ma from low-frequency anomalies off-axis to high-frequency anomalies towards the present axis. This potentially represents the stage at which buried spreading centres became exposed. In this interpretation, intrusions such as sills at the buried spreading centre led to broad magnetic anomalies, whereas the later exposure of the spreading centre led to a more typical development of crustal magnetization by rapid cooling of extrusives.

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43

Uchanin, V. M., S. M. Minakov, and R. M. Solomakha. "Research of the residual magnetization of steel structures after local magnetization with an attachable magnetic transducer." Paton Welding Journal 2024, no. 3 (March 28, 2024): 46–50. http://dx.doi.org/10.37434/tpwj2024.03.07.

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44

Ravat, Dhananjay. "Magnetic properties of unrusted steel drums from laboratory and field‐magnetic measurements." GEOPHYSICS 61, no. 5 (September 1996): 1325–35. http://dx.doi.org/10.1190/1.1444056.

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Laboratory‐derived magnetic properties from samples of steel drums appear to be lower than bulk magnetic properties required to produce observed magnetic anomalies over the same drums. The origin of this discrepancy is perhaps in the shape demagnetization experienced by samples used in the laboratory study. Laboratory observations of magnetic susceptibility in different directions suggest that the demagnetization mechanism may have significantly attenuated the laboratory‐derived magnetization values from small samples of drums. Field observations and computer modeling indicate that even though the effect of demagnetization is important for drum‐shaped objects, demagnetization is less pronounced in the shape of the drum than in the samples cut for laboratory measurements. Therefore, laboratory‐derived magnetizations from samples of steel drums cannot be used to model magnetic anomalies of steel drums. If laboratory‐derived magnetizations were used to model steel drums, the models would underestimate the resulting magnetic anomalies considerably and, in turn, would overestimate the number of buried drums at an environmental investigation site. Apparent bulk magnetization values for unrusted vertically oriented 55 and 30 gallon drums have been calculated (i.e., the values corrected for the effect of shape demagnetization of the drums). These range from ∼90 to ∼125 SI units (∼7 to ∼10 cgs units) for volume susceptibility and from ∼325 to ∼2750 A/m (∼0.325 to [Formula: see text]) for remanent magnetization (based on eight 55 gallon and four 30 gallon drums). Further deviations in these values could arise from the type and thickness of the steel and variations in manufacturing conditions affecting magnetizations. From the point of view of modeling the drums, at most source‐to‐observation distances applicable to environmental investigations, the equivalent source method is able to approximate the observed anomalies of steel drums better than the 3-D modeling method. With two years of rusting, magnetic anomalies of some of the drums have reduced, while in other drums, they have slightly increased. The overall magnetic changes caused by rusting appear to be more complex than anticipated, at least in the initial phase of rusting.

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BROWN, P. J. "MAGNETIZATION DISTRIBUTIONS." International Journal of Modern Physics B 07, no. 16n17 (July 30, 1993): 3029–48. http://dx.doi.org/10.1142/s0217979293003140.

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The determination of magnetization distributions using neutron scattering is not a new technique but one that has developed over the last 30 years. In the present article a brief introduction to the technique is given, methods used for the analysis of the data obtained are critically reviewed, and some of the new results which have been obtained in the last five years are presented. Attention is concentrated on examples for which the results obtained have helped to answer questions in areas of high current interest.

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Bartkowska, Joanna, Jan Cisowski, Jean Voiron, Jan Heimann, Maria Czaja, and Zbigniew Mazurak. "Magnetization and magnetic susceptibility of jadeite." European Journal of Mineralogy 16, no. 4 (July 15, 2004): 671–75. http://dx.doi.org/10.1127/0935-1221/2004/0016-0671.

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47

Gee, J., H. Staudigel, and L. Tauxe. "Contribution of induced magnetization to magnetization of seamounts." Nature 342, no. 6246 (November 1989): 170–73. http://dx.doi.org/10.1038/342170a0.

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Burzo, Emil, and Romulus Tetean. "New Insights on the Spin Glass Behavior in Ferrites Nanoparticles." Nanomaterials 12, no. 10 (May 23, 2022): 1782. http://dx.doi.org/10.3390/nano12101782.

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The magnetic properties of nanocrystalline MxFe3−xO4 ferrites with M=Fe, Co, and Zn were investigated. The data support a core–shell model, where the core is ferrimagnetically ordered, and the shell shows a spin glass type behavior. The reduced magnetizations of spin glass components follow an mg = (1 – b/H−1/2) field dependence. The b values are strongly correlated with the intensities of exchange interactions. The field dependences of the magnetoresistances of Fe3O4 and ZnxFe3−xO4 nanoparticles pellets, experimentally determined, are well described if instead of the core reduced magnetization, commonly used, that of the shell is taken into account. For similar compositions of the nanoparticles, identical b values are obtained both from magnetization isotherms and magnetoresistances studies. The half-metallic behavior of spinel Fe3O4 based nanoparticles is discussed comparatively with those of double perovskites.

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Kamihoki, Uraku, Yuichiro Kurokawa, Masahiro Fujimoto, and Hiromi Yuasa. "Inversion symmetry breaking in spin–orbit torque-induced magnetization switching to improve the recording density of multi-level magnetoresistive random-access memory." Journal of Applied Physics 133, no. 14 (April 14, 2023): 143902. http://dx.doi.org/10.1063/5.0131540.

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In this study, we prepared a multi-layer Tb–Fe/Pt/Tb–Fe wire to develop a multi-level magnetic memory. By applying current, magnetizations of the Tb–Fe layers were inversion symmetrically switched by spin– orbit torque (SOT) generated from the middle Pt layer. Measurements of SOT showed that its efficiency had opposite polarities in the top and bottom Tb–Fe layers. The switching current density of the top and bottom Tb–Fe layers shifted in opposite directions under a uniform perpendicular magnetic field. Because the perpendicular magnetic field broke the inversion symmetry of SOT generated from the middle Pt layer, it could be used to control the switching current. Our results prove that the additional uniform and perpendicular magnetic field can enhance the controllability of the magnetization state in case of multi-level SOT-induced magnetization switching.

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Li, Yaoguo, Jiajia Sun, Shu-Ling Li, and Marcelo Leão-Santos. "A paradigm shift in magnetic data interpretation: Increased value through magnetization inversions." Leading Edge 40, no. 2 (February 2021): 89–98. http://dx.doi.org/10.1190/tle40020089.1.

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Abstract:

Magnetic data are sensitive to both the induced magnetization in rock units caused by the present earth's magnetic field and the remanent magnetization acquired by rock units in past geologic time. Susceptibility is a direct indicator of the magnetic mineral content, whereas remanent magnetization carries information about the formation process and subsequent structural movement of geologic units. The ability to recover and use total magnetization, defined as the vectorial sum of the induced and remanent magnetization, therefore enables us to take full advantage of magnetic data. The exploration geophysics community has achieved significant advances in inverting magnetic data affected by remanent magnetization. It is now feasible to invert any magnetic data set for total magnetization. We provide an overview of the state of the art in magnetization inversion and demonstrate the informational value of inverted magnetization through a set of case studies from mineral exploration problems. We focus on the methods that recover either the magnitude of the total magnetization or the total magnetization vector itself.

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Journal articles on the topic 'Magnetization'

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