Journal articles: 'Rare earth ion dopants'

1

Tay, Jian Wei, Patrick M. Ledingham, and Jevon J. Longdell. "Coherent optical ultrasound detection with rare-earth ion dopants." Applied Optics 49, no. 23 (August 3, 2010): 4331. http://dx.doi.org/10.1364/ao.49.004331.

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Lv, Yang, Yahong Jin, Zhenzhang Li, Shaoan Zhang, Haoyi Wu, Guangting Xiong, Guifang Ju, Li Chen, Zhengfa Hu, and Yihua Hu. "Reversible photoluminescence switching in photochromic material Sr6Ca4(PO4)6F2:Eu2+ and the modified performance by trap engineering via Ln3+ (Ln = La, Y, Gd, Lu) co-doping for erasable optical data storage." Journal of Materials Chemistry C 8, no. 19 (2020): 6403–12. http://dx.doi.org/10.1039/d0tc00933d.

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Dasgupta, V., N. Litombe, W. E. Bailey, and H. Bakhru. "Ion implantation of rare-earth dopants in ferromagnetic thin films." Journal of Applied Physics 99, no. 8 (April 15, 2006): 08G312. http://dx.doi.org/10.1063/1.2173212.

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Sun, Yifei, Michele Kotiuga, Dawgen Lim, Badri Narayanan, Mathew Cherukara, Zhen Zhang, Yongqi Dong, et al. "Strongly correlated perovskite lithium ion shuttles." Proceedings of the National Academy of Sciences 115, no. 39 (August 13, 2018): 9672–77. http://dx.doi.org/10.1073/pnas.1805029115.

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Solid-state ion shuttles are of broad interest in electrochemical devices, nonvolatile memory, neuromorphic computing, and biomimicry utilizing synthetic membranes. Traditional design approaches are primarily based on substitutional doping of dissimilar valent cations in a solid lattice, which has inherent limits on dopant concentration and thereby ionic conductivity. Here, we demonstrate perovskite nickelates as Li-ion shuttles with simultaneous suppression of electronic transport via Mott transition. Electrochemically lithiated SmNiO3 (Li-SNO) contains a large amount of mobile Li+ located in interstitial sites of the perovskite approaching one dopant ion per unit cell. A significant lattice expansion associated with interstitial doping allows for fast Li+ conduction with reduced activation energy. We further present a generalization of this approach with results on other rare-earth perovskite nickelates as well as dopants such as Na+. The results highlight the potential of quantum materials and emergent physics in design of ion conductors.

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Kang, Fengwen, Lejing Li, Jin Han, Dang Yuan Lei, and Mingying Peng. "Emission color tuning through manipulating the energy transfer from VO43− to Eu3+ in single-phased LuVO4:Eu3+ phosphors." Journal of Materials Chemistry C 5, no. 2 (2017): 390–98. http://dx.doi.org/10.1039/c6tc04172h.

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Recently, rare earth (RE) ion doped single-phased phosphors, which can emit tunable colors upon single wavelength excitation, have received a great deal of attention, but most of them involve multiple dopants as luminescence centers.

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Frayret, Christine, Antoine Villesuzanne, Michel Pouchard, Fabrice Mauvy, Jean Marc Bassat, and Jean Claude Grenier. "A Density Functional Study of Oxygen Mobility in Ceria-Based Materials." Defect and Diffusion Forum 323-325 (April 2012): 233–38. http://dx.doi.org/10.4028/www.scientific.net/ddf.323-325.233.

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In CeO2-based solid electrolytes, it has been shown that point defects are directly responsible for oxygen ionic conduction. The ionic conductivity is strongly affected by the anion vacancy concentration which is enhanced by doping with aliovalent cations. When rare earth sesquioxides such as La2O3, Gd2O3, Sm2O3, Y2O3 are added to CeO2, the dopant cation substitutes for the cerium ion, and oxygen vacancies are created for charge compensation. Incorporation of trivalent dopants into CeO2 at the Ce4+ sites can be depicted by the following defect reaction (expressed in Kröger-Vink notation):

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OGURI, Yasuo, Ryuji ADACHI, Hideo TONO, Norio NAKAJIMA, and Tadashi ENDO. "The Effect of Rare Earth Ion Dopants on the Grain Size of Y2O2S Phosphors." Journal of the Ceramic Society of Japan 104, no. 1216 (1996): 1129–32. http://dx.doi.org/10.2109/jcersj.104.1129.

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Caratto, Valentina, Federico Locardi, Giorgio Andrea Costa, Roberto Masini, Mauro Fasoli, Laura Panzeri, Marco Martini, Emanuela Bottinelli, Enrica Gianotti, and Ivana Miletto. "NIR Persistent Luminescence of Lanthanide Ion-Doped Rare-Earth Oxycarbonates: The Effect of Dopants." ACS Applied Materials & Interfaces 6, no. 20 (October 13, 2014): 17346–51. http://dx.doi.org/10.1021/am504523s.

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Hasim, Nurhafizah, Md Supar Rohani, Md Rahim Sahar, and Sib Krishna Ghoshal. "Luminescence of Er³⁺/Nd³⁺ Co-Doped Lithium Niobate Tellurite Glass." Materials Science Forum 846 (March 2016): 131–36. http://dx.doi.org/10.4028/www.scientific.net/msf.846.131.

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Achieving tuneable photoluminescence via controlled co-doping of rare earth ions in lithium niobate based glasses are challenging. A series of Er3+/ Nd3+ co-doped tellurite glasses of composition (70-x-y) TeO2 – 15 Li2CO3 – 15 Nb2O5 – (x) Er2O3 – (y) Nd2O3 with x = 0; 1.0 mol % and 0 ≤ y ≤ 1.0 mol % are prepared using melt quenching technique. The influence of co-dopants on the emission properties is analyzed and discussed using partial energy level diagram of rare earth ions. The dopants concentration dependent physical properties such as refractive index, molar volume, density, polarizability and molar refractions are determined. The down-converted luminescence spectra for 2G9/2 à4I9/2 transition reveal a strong green emission band centred at 497 nm is attributed to the energy transfer from erbium to neodymium ion. The emission spectra exhibit five prominent peaks centred at 497, 539, 553, 616 and 634 nm corresponding to the transitions from 2H11/2, 4S3/2 and 4F9/2 excited states to the ground state of Er3+ ion and the transitions from 2G9/2, 2G7/2, 2H11/2 and 4F9/2 excited states to ground state of Nd3+ ion. The highest intensity is achieved for x = y = 1.0 mol%. The excellent luminescence response suggests that our glasses may be nominated for solid state lasers and other photonic applications.

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Nilsson, Johan O., Mikael Leetmaa, Olga Yu Vekilova, Sergei I. Simak, and Natalia V. Skorodumova. "Oxygen diffusion in ceria doped with rare-earth elements." Physical Chemistry Chemical Physics 19, no. 21 (2017): 13723–30. http://dx.doi.org/10.1039/c6cp06460d.

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Zhang, Lin, Chen Shu Li, Hiroshi Yamada, and Chao Nan Xu. "A Novel Blue-Violet Emitting Mechanoluminescent Material with Calcium Aluminosilicate." Key Engineering Materials 388 (September 2008): 277–80. http://dx.doi.org/10.4028/www.scientific.net/kem.388.277.

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We have demonstrated a novel blue-violet emitting mechanoluminscent(ML) material with calcium aluminosilicate(CaAl2Si2O8:Eu2+). The ML was clearly visible to the naked eye in the atmosphere and showed a similar spectrum to photoluminescence with a peak at 430nm. In order to enhance the ML intensity, various rare earth ions were selected as co-dopants including La, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu. It was found that the intensity of ML was strongly dependent on the kinds of the codoped rare earth ion, especially the co-doping of Ho3+ was found to greatly enhance the ML intensity. From the results of thermoluminescence(ThL) measurements, the enhancement of the ML intensity was closely related with the filled trap concentration and trap depth.

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Kling, Andreas, and José G. Marques. "Unveiling the Defect Structure of Lithium Niobate with Nuclear Methods." Crystals 11, no. 5 (May 2, 2021): 501. http://dx.doi.org/10.3390/cryst11050501.

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X-ray and neutron diffraction studies succeeded in the 1960s to determine the principal structural properties of congruent lithium niobate. However, the nature of the intrinsic defects related to the non-stoichiometry of this material remained an object of controversial discussion. In addition, the incorporation mechanism for dopants in the crystal lattice, showing a solubility range from about 0.1 mol% for rare earths to 9 mol% for some elements (e.g., Ti and Mg), stayed unresolved. Various different models for the formation of these defect structures were developed and required experimental verification. In this paper, we review the outstanding role of nuclear physics based methods in the process of unveiling the kind of intrinsic defects formed in congruent lithium niobate and the rules governing the incorporation of dopants. Complementary results in the isostructural compound lithium tantalate are reviewed for the case of the ferroelectric-paraelectric phase transition. We focus especially on the use of ion beam analysis under channeling conditions for the direct determination of dopant lattice sites and intrinsic defects and on Perturbed Angular Correlation measurements probing the local environment of dopants in the host lattice yielding independent and complementary information.

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Apostolova, Iliana, Angel Apostolov, and Julia Wesselinowa. "Magnetic, Phonon and Optical Properties of Transition Metal and Rare Earth Ion Doped ZnS Nanoparticles." Nanomaterials 13, no. 1 (December 23, 2022): 79. http://dx.doi.org/10.3390/nano13010079.

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The surface, size and ion doping effects on the magnetic, phonon and optical properties of ZnS nanoparticles are studied based on the s-d model including spin-phonon and Coulomb interaction, and using a Green’s function theory. The changes of the properties are explained on a microscopic level, due to the different radii between the doping and host ions, which cause different strains—compressive or tensile, and change the exchange interaction constants in our model. The magnetization increases with increasing small transition metal (TM) and rare earth (RE) doping concentration. For larger TM dopants the magnetization decreases. The phonon energies increase with increasing TM, whereas they decrease by RE ions. The phonon damping increases for all doping ions. The changes of the band gap energy with different ion doping concentration is also studied. Band gap changes in doped semiconductors could be due as a result of exchange, s-d, Coulomb and electron-phonon interactions. We have tried to clarify the discrepancies which are reported in the literature in the magnetization and the band gap energy.

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Antić-Fidančev, E. "Evidence of Dopant-Matrix Interaction in Optical Spectra of Rare Earth Ions." Materials Science Forum 494 (September 2005): 253–58. http://dx.doi.org/10.4028/www.scientific.net/msf.494.253.

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Complex emission spectra of europium doped rare earth calcium oxoborates, EuCa4O(BO3)3 - EuCOB, and GdCa4O(BO3)3: Eu3+- GdCOB: Eu3+, were finely analyzed for better understanding of some local perturbations detected in these solid media. Highlighting a “size effect” of dopant / matrix ions, the interaction between the host lattice and the embedded ion is demonstrated. The evolution of the crystal field strength of R3+ ions along the rare earth series is presented for C-type RE2O3 oxides. According to R3+ - RE3+ ionic radii difference (R3+ for a dopant ion and RE3+ for a matrix ion), two opposite standings are evidenced along a series. Effect of high concentration doping on spectral line broadening is illustrated following a half-height width of 2P1/2 level of Nd3+ ion in A-type La2O3 oxide.

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Le Coq, Yann, Klaus Mølmer, and Signe Seidelin. "Position- and momentum-squeezed quantum states in micro-scale mechanical resonators." Modern Physics Letters B 34, no. 17 (March 18, 2020): 2050193. http://dx.doi.org/10.1142/s0217984920501936.

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A challenge of modern physics is to investigate the quantum behavior of a bulk material object, for instance a mechanical oscillator. We have earlier demonstrated that by coupling a mechanical oscillator to the energy levels of embedded rare-earth ion dopants, it is possible to prepare such a resonator in a low phonon number state. Here, we describe how to extend this protocol in order to prepare momentum- and position-squeezed states, and we analyze how the obtainable degree of squeezing depends on the initial conditions and on the coupling of the oscillator to its thermal environment.

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Ejigu A, Afrash, K. P. Ramesh, and Gajanan Honnavar. "Vibrational, Thermal, and Physical Characterizations of Some Zinc Niobo Tellurite Glasses Doped with Rare Earth (Eu, Dy)-=SUP=-*-=/SUP=-." Оптика и спектроскопия 129, no. 4 (2021): 527. http://dx.doi.org/10.21883/os.2021.04.50785.1012-20.

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In this communication, we report physical and thermal properties along with Raman spectroscopic investigations on Zinc Niobo Tellurite glass systems doped with Eu2O3 and Dy2O3 at the expense of TeO2. The glasses have been synthesized by the melt quenching technique. Physical parameters like density, molar volume, packing density were estimated. The density of the un-doped glasses increases with increasing mol% of the modifier (ZnO) whereas the glass transition temperature (Tg) decreases. We have observed an increase in the density of the base glass systems which are doped with rare earth (RE) dopants. The packing density of the un-doped glasses remains almost constant with increasing modifier content suggesting that there is not much change in the local environment. Raman spectra were recorded at room temperature and assigned to TeO4 and TeO3 structural units in these glasses. The peak shift, full width at half maximum (FWHM) of the de-convoluted Raman peaks were analyzed to get information about the local environment. It is observed that these compositions of tellurite glasses are good host materials for rare earth ions as they offer voids in the network. Further, it was observed that the rare earth ion doping has not affected the local environment of the glasses; Dy3+ ions have a slightly higher tendency to polarize Te-O bonds than the Eu3+ ions. Keywords: Niobium-based tellurite glasses, XRD, DSC, FTIR.

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17

Mahraz, Zahra Ashur Said, M. R. Sahar, and Sib Krishna Ghoshal. "Influence of Er³⁺ Dopants on Optical Properties of Boro-Tellurite Glass." Advanced Materials Research 895 (February 2014): 211–15. http://dx.doi.org/10.4028/www.scientific.net/amr.895.211.

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The effect of the rare earth ion concentration on the physical and spectroscopic properties of Er3+-doped boro-tellurite glass is studied. Glasses with compositions 30B2O3+10ZnO+(60-x)TeO2+xEr2O3(where x=0, 0.5, 1, 1.5 and 2mol%) are prepared by melt-quenching method. The structural analyses are made through XRD, FTIR and UV-VIS-IR absorption spectroscopy. IR-spectra reveal five absorption bands in the region of 450-1500 cm-1for different B-O and Te-O vibrational groups. The UV-VIS-IR spectra exhibits seven absorption bands corresponding to the transitions from4I15/2ground state to4I13/2,4I11/2,4I9/2,4F9/2,2H11/2,4F7/2and4F3/2excited states. The bonding parameters are determined from the optical absorption spectra and are found to be covalent in nature. The optical band gap energy values corresponding to the direct and indirect allowed transitions decreases while the Urbach energy and cut-off wavelengths increases by the introduction of Er3+ions. Keywords: Er3+ions, melt-quenching, boro-tellurite glass, optical band gap

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Guan, Mingyun, Jianhua Sun, Feifei Tao, and Zheng Xu. "A Host Crystal for the Rare-Earth Ion Dopants: Synthesis of Pure and Ln-Doped Urchinlike BiPO4Structure and Its Photoluminescence." Crystal Growth & Design 8, no. 8 (August 2008): 2694–97. http://dx.doi.org/10.1021/cg070642z.

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GUO-LI, SONG. "LUMINESCENCE CHARACTERISTICS OF RARE-EARTH ERBIUM ION-DOPED NANOCRYSTALLINE ZINC OXIDE." Journal of Nonlinear Optical Physics & Materials 18, no. 04 (December 2009): 649–56. http://dx.doi.org/10.1142/s0218863509004853.

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Er3+ -doped ZnO nanocrystalline powders are successfully prepared by the chemical precipitation method, using various doping concentrations of Er3+ at different annealing temperatures from 500°C to 900°C. The characteristic emission peaks of the excitation state 4S3/2 (550 nm), 2 H 11/2 (520 nm), 4 F 5/2 (455 nm) → 4 I 15/2 transition of Er3+ ions are observed in a wide visible band of the ZnO host. The relationship between the PL intensity of integration of nanocrystalline ZnO:Er3+ and the annealing temperature and doping concentration of Er3+ is given; it is found that the optimal dopant concentration and annealing temperature are 4.0 × 10-3 M and 850°C for the 4 S 3/2 → 4 I 15/2 (550 nm) and 4 F 5/2 → 4 I 15/2 (455 nm) transition of Er3+ . Based on these results, the mechanism of the emission spectra of ZnO is analyzed and its defects on the spectral properties are discussed. An energy transfer from excited states of ZnO hosts to doping Er3+ ion centers is revealed by the fact that PL intensity of the peaks of nanocrystalline ZnO:Er3+ changes with the annealing temperature and doping concentration of Er3+ , and another from the 4f–4f transition of Er3+ .

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Vivona, Marilena, and Michalis Zervas. "Instrumentation for Simultaneous Non-Destructive Profiling of Refractive Index and Rare-Earth-Ion Distributions in Optical Fiber Preforms." Instruments 2, no. 4 (November 7, 2018): 23. http://dx.doi.org/10.3390/instruments2040023.

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We present a non-destructive technique for a combined evaluation of refractive index and active-dopant distribution in the same position along a rare-earth-doped optical fiber preform. The method relies on luminescence measurements, analyzed through an optical tomography technique, to define the active dopant distribution and ray-deflection measurements to calculate the refractive index profile. The concurrent evaluation of both the preform refractive index and the active dopant profiles allows for an accurate establishment of the dopant distribution within the optical core region. This combined information is important for the optimization and development of a range of advanced fibers, used, for example, in a high-power fiber lasers and modern spatial-division-multiplexing optical communication systems. In addition, the non-destructive nature allows the technique to be used to identify the most appropriate preform segment, thus increasing fiber yield and reducing development cycles. We demonstrate the technique on an Yb3+-doped aluminosilicate fiber preform and compare it with independent refractive index and active-dopant measurements. This technique will be useful for quality evaluation and optimization of optical fiber preforms and lends itself to advanced instrumentation.

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Luo, Zheyu, Yucun Zhou, Xueyu Hu, and Meilin Liu. "(Invited) Recent Progress in the Development of Highly Durable and Conductive Proton Conductors for High-Performance Reversible Solid Oxide Cells." ECS Meeting Abstracts MA2022-02, no. 49 (October 9, 2022): 1904. http://dx.doi.org/10.1149/ma2022-02491904mtgabs.

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Proton conductor-based solid oxide fuel cells (SOFCs) and electrolysis cells (SOECs) are receiving increasing attention because of their potential for operation at intermediate temperatures (400 - 600 oC) with high energy efficiency at low cost. In addition, water is formed/provided on the air electrode side of proton-conducting cells, effectively avoiding fuel dilution and nickel oxidation problems associated with oxide-ion conductor-based cells. To date, doped barium cerates-based perovskite oxides are the most widely adopted proton conducting electrolytes due to their desired electrochemical properties. To achieve high proton conductivity, acceptor doping with rare earth elements is a commonly used strategy, which is critical to the formation of protonic defects. Although many trivalent elements have been studied as dopants in the barium cerate family and reasonable electrochemical performance has been demonstrated, the effect of acceptor dopants on other properties of electrolyte materials, especially in single cells under operating conditions, is yet to be studied in detail. In this presentation, we will report our recent progress in the development of a series of acceptor-doped proton-conducting electrolytes. The results reveal that conductivity, transference number, chemical stability, and compatibility with NiO are all closely correlated with dopant size. In particular, the reactivity with NiO is found to strongly affect the properties of the electrolytes and hence cell performance. Among all tested compositions, an optimized electrolyte shows excellent chemical stability and minimal reactivity towards NiO, as predicted from density functional theory (DFT)-based calculations and confirmed by experimental results. In addition, reversible protonic ceramic electrochemical cells (R-PCECs) based on the optimized electrolyte demonstrate exceptional performance and stability, achieving a remarkable peak power density of 1.2 W cm-2 at 600 oC in the fuel cell mode and a high current density of 2.0 A cm-2 at 1.3 V and 600 oC in the steam electrolysis mode while maintaining long-term durability for over 1000 h without obvious degradation.

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Wang, Rongfang, Xingming Wei, Pingfang Tao, Qinmin Wei, Pei Zhang, and Yiguang Tan. "Aqueous synthesis of thioglycollic acid-capped Tb3+-doped cadmium sulfur quantum dots." Nanomaterials and Nanotechnology 7 (December 28, 2016): 184798041668080. http://dx.doi.org/10.1177/1847980416680809.

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Cadmium sulfur nanocrystals doped with the rare earth ion Tb3+ were synthesized using an easy aqueous method. Powder X-ray diffraction was used for the crystallography analysis of the nanocrystals. Results showed that cadmium sulfur: Tb3+ quantum dots had a cubic crystal structure. Effects of the pH of the original solution and Tb3+-dopant amount on luminescence properties of cadmium sulfur quantum dots were also systematically investigated. The luminescence properties of cadmium sulfur quantum dots were further improved using an appropriate Tb3+-dopant amount.

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W. L., Fong, Sharudin Omar Baki, N. M. Arifin, Yaakob Mansor, Ahmad Nazri, and Bashar Khudhair Abbas. "Structural, Thermal and Optical Properties of Rare Earth Doped Lead-Tellurite Oxide Glasses." Journal of Advanced Research in Fluid Mechanics and Thermal Sciences 81, no. 2 (March 25, 2021): 52–58. http://dx.doi.org/10.37934/arfmts.81.2.5258.

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Structural, thermal and optical properties of lead-tellurite oxide glasses consisting TeO2 – PbO – Bi2O3 – Er2O3, synthesized by high temperature melt-quenching-thermal annealing method were investigated in this study. The role of rare-earth element, erbium ion as dopant into the host glass has affected physically, thermally and optically of the glasses. The amorphous nature of the glasses was confirmed by XRD (x-ray diffraction). Thermal exo-endothermic event profiles clarify its glass transformation temperature Tg, crystallization temperature Tx, and melting temperature Tm are exist. Both UV-Vis-NIR optical absorption and Raman spectroscopy have revealed optical energy gap changes due to the structural deformation by the erbium ions. Related obtained glass parameters such as polarizability, refractive indices and metallization criterion were also explained further in this study.

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Vidya, Y. S., and B. N. Lakshminarasappa. "Influence of Rare Earth Doping on Microstructure and Luminescence Behaviour of Sodium Sulphate." Indian Journal of Materials Science 2014 (January 6, 2014): 1–8. http://dx.doi.org/10.1155/2014/675417.

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Na2SO4, Na2SO4: Li, and Na2SO4: Li, Eu, Dy phosphors were prepared by using slow evaporation technique followed by subsequent calcination at 400°C for 4 h. Doping with Li+ ion stabilized the thenardite phase of host matrix, while codoping with RE3+ stabilized the phase transformation from stable thenardite to metastable mirabilite crystal structure. The microstructure and morphology were studied by using scanning electron microscopy and transmission electron microscopy. The thermoluminescence studies revealed that isovalent doping of Li+ served as a quencher and addition of codopant introduces the additional trap sites in the host matrix. The room temperature emission spectra of Li-doped, RE3+-codoped, and undoped Na2SO4 were studied under ultraviolet radiation. For pure Na2SO4 the two peaks which appeared are at 364 and 702 nm, respectively. The emission intensities of RE3+-codoped samples increase with increase in dopant concentration.

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Secu, C. E., R. F. Negrea, and M. Secu. "Eu3+ probe ion for rare-earth dopant site structure in sol–gel derived LiYF4 oxyfluoride glass–ceramic." Optical Materials 35, no. 12 (October 2013): 2456–60. http://dx.doi.org/10.1016/j.optmat.2013.06.053.

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Harrington, George Frederick, Nicola H. Perry, Kazunari Sasaki, Bilge Yildiz, and Harry L. Tuller. "The Interplay of Strain and Defect Association on the Conductivity Rare Earth Substituted CeO₂." ECS Meeting Abstracts MA2018-01, no. 32 (April 13, 2018): 1944. http://dx.doi.org/10.1149/ma2018-01/32/1944.

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In solid state oxygen ion conductors such as CeO2 and ZrO2, aliovalent cations are used to introduce oxygen vacancies which allow ionic conduction, but which also limit the maximum achievable conductivity due to defect-defect interactions. Materials are optimised based on the size and concentration of the substituted cations, in order to minimise defect association and maximise ionic transport. To push the performance of such materials beyond their compositional limit, significant attention has turned to the application of mechanical strain. Computational studies have shown that the energy barrier for migration in CeO2 and ZrO2 can be manipulated using lattice strain. A number of studies are in broad agreement, showing that significant enhancements in the conductivity under tensile strain can be achieved.[1],[2] However, experimentally, the results on strained thin films and multilayers have been both controversial and inconstant, with vastly different findings in nominally similar systems.[3] Typically strained layers due to interfacial mismatch are grown and the thickness varied to control the volume fraction of the strained material. However this leads to difficulties controlling the density of grain boundaries, and isolating changes in the conductivity in the layers.[4] These complications mean that comparisons between experimental and computational work are challenging. Furthermore, much of the work so far on the effects of strain on the transport properties have focused on the so-called ‘optimised’ ionic conductors, such as commercial electrolytes Y-stabilised ZrO2 or Gd- or Sm-doped CeO2. Very little attention has been payed to the ‘non-optimised’ electrolytes where the defect-defect interactions are much more significant. However, as the defect association limits the conductivity for these materials a much larger enhancement in the transport properties (or a less significant reduction) due to strain may be possible. We have fabricated both ‘optimised’ and ‘non-optimised’ doped-CeO2 films by pulsed laser deposition on MgO substrates. The dopants used were La, Gd, and Yb, which represent an ionic radii mismatch with the host Ce lattice of 19.6%, 8.6%, and 1.5% respectively. Epitaxy was maintained using a double BaZrO3 and SrTiO3 buffer layer resulting in films free from grain boundaries. The thickness of the films was kept constant and the strain varied by thermal annealing (from 600°C to 1000°C) to relax the intrinsic strain occurring during growth. Crucially, this means that the strain in these materials can be tailored and the conductivity measured without complications due to grain boundary effects or changes in the volume fraction of the interface and surface. The out-of-plane and in-plane strain in the films was characterised in detail using X-ray diffraction and Raman spectroscopy, and the microstructure evaluated by high-resolution transmission electron microscopy. Impedance spectroscopy measurements showed that the conductivity of the relaxed films was in excellent agreement with bulk rare earth substituted CeO2. With increasing in-plane compressive strain, the conductivity of the films was reduced and the activation energy increased. The observed change in the activation energy with strain is in excellent agreement with computational work, and consistent with other experimental findings. In addition we show that the effect is more pronounced for Yb-substituted CeO2 than La- or Gd-substituted CeO2, suggesting that larger changes in the conductivity with strain can be obtained with ‘non-optimised’ dopant cations. [1] A. Kushima and B. Yildiz, “Oxygen ion diffusivity in strained yttria stabilized zirconia: where is the fastest strain?,” J. Mater. Chem., vol. 20, no. 23, p. 4809, 2010. [2] R. A. De Souza, A. Ramadan, and S. Hörner, “Modifying the barriers for oxygen-vacancy migration in fluorite-structured CeO2 electrolytes through strain: a computer simulation study,” Energy Environ. Sci., vol. 5, no. 1, p. 5445, 2012. [3] K. Wen, W. Lv, and W. He, “Interfacial lattice-strain effects on improving the overall performance of micro-solid oxide fuel cells,” J. Mater. Chem. A, vol. 3, no. 40, pp. 20031–20050, 2015. [4] G. F. Harrington, A. Cavallaro, D. W. McComb, S. J. Skinner, and J. A. Kilner, “The effects of lattice strain, dislocations, and microstructure on the transport properties of YSZ films,” Phys. Chem. Chem. Phys., vol. 19, pp. 14319–14336, 2017.

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Karthickprabhu, S., G. Hirankumar, S. Thanikaikarasan, and P. J. Sebastian. "Structural, Thermal and Electrical Conduction Studies on LiNiPO4: RE (RE= La, Nd) Prepared by Polyol Method." Journal of New Materials for Electrochemical Systems 17, no. 3 (October 3, 2014): 159–66. http://dx.doi.org/10.14447/jnmes.v17i3.416.

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LiNiPO4 and LiNiPO4: xRE (RE = La, Nd) (x = 0.01 mol%, 0.03 mol%, 0.05 mol%, 0.07 mol%, 0.09 mol%) samples have been prepared by polyol method using 1, 2 propanediol as a polyol medium. XRD patterns have indicated that the pristine LiNiPO4 is well crystallized with orthorhombic structure pnma space group and structurally stable compound upon doping of rare earth metals. Functional group analyses have been carried out by FTIR spectroscopic analysis. TG analysis shows that no weight loss has been observed above 600°C for both Nd3+ and La3+ doped LiNiPO4. The morphology of the samples was analyzed through Scanning Electron Microscopy. The conductivity of LiNiPO4 was found to be improved by 2 orders by doping of rare earth ions. It is found that lanthanum is an excellent dopant for LiNiPO4 than neodymium due to the formation of free ion sites which causes the enhancement of conductivity. Dielectric studies support that doping of La3+ is favorable for conduction compared with Nd3+ doping.

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Li, Wen-Hao, Yu-Qing Xie, Hai-Zheng Shi, Peng-Fei Lu, and Jing Ren. "Mechanisms of rare earth ion distribution in fluorosilicate glass containing KMnF3 nanocrystal." Acta Physica Sinica 71, no. 8 (2022): 084205. http://dx.doi.org/10.7498/aps.71.20211953.

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Luminescent materials with an efficient single-(pure) color up-conversion luminescence (UCL) are expected to be applied to three-dimensional(3D) display, lighting, biological imaging, promoting plant growth and improving the photoelectric conversion efficiency of solar cells. In this work, perovskite-type KMnF3 fluoride nanocrystals (NCs) are grown in situ in a fluorosilicate glass co-doped with rare earth (RE) ions Yb3+/Er3+ by a controlled thermal treatment. Compared with precursor glass (PG), the nano-glass composites (also referred to as glass ceramics, or GC in short) thus obtained exhibit a significantly enhanced (by 6 times) red UCL emission. Although a weak green UCL emission can be also observed in the GC, the intensity ratio of the red UCL emission to green UCL emission is as high as 30, implying a good color purity. It is suggested that the dramatic enhancement of UCL emissions in the GCs is due to the doping of RE ions into the KMnF3 NCs with a much lower phonon energy (330 cm–1) than that of the silica glass matrix about 1100 cmv1. However, the doping mechanisms of RE ions into KMnF3 nano-glass composites are not yet conclusive, mainly because of the charge and ionic radius mismatch between RE ion dopants and cations of KMnF3. This work combines the high-resolution transmission electron microscopy (HR-TEM) analysis technology and the first principles calculation, to unravel the doping mechanism of RE ions in KMnF3 nano-glass composites. First, the HR-TEM study provides straightforward evidence that RE ions are preferentially accumulated in KMnF3 NCs embedded in the glass matrix. Then, through the first-principles calculation considering the charge balance, it is found that the formation energy of RE ions substituting for K+ is lower than for Mn2+ lattice sites in KMnF3, which is most likely related to the fact that the ionic radius of the eight-fold coordinated K+ is larger than that of the six-fold coordinated Mn2+ and thus is more conductive to accommodating the large size RE ions. The electronic densities of states at the top of the valence band and the bottom of the conduction band of KMnF3 increase after doping the RE ions. It is inferred from the profile of partial density of state that RE ions have a strong bonding tendency with F- in the crystal. Benefiting from the efficient energy transfer between RE ions and Mn2+ in KMnF3, the green UCL emission is dramatically quenched, and consequently, the GC is endowed with a highly pure red UCL emission. The present study is expected to deepen the understanding of RE ions doping mechanisms in NCs and facilitate the design of highly efficient UCL materials based on nano-glass composites.

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29

Zhang, Nan, Lie Wang, Qingyu Diao, Kongying Zhu, Huan Li, Chuanwei Li, Xingjiang Liu, and Qiang Xu. "Mechanistic Insight into La₂O₃ Dopants with High Chemical Stability on Li₃PS₄ Sulfide Electrolyte for Lithium Metal Batteries." Journal of The Electrochemical Society 169, no. 2 (February 1, 2022): 020544. http://dx.doi.org/10.1149/1945-7111/ac51fb.

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Unlike the unstable liquid-state organic electrolyte at high temperatures, the solid-state electrolytes with high safety have attracted a broad prospect for the development of all-solid-state lithium metal battery (ASSLMB). Among the solid electrolytes, the sulfide-based electrolyte with low grain boundary resistances is one of the most practical choices due to its high lithium-ionic conductivity. The introduction of non-conducting oxide fillers into sulfide matrix is an effective way to increase their ionic conductivities and interfacial stabilities with the electrodes of battery simultaneously. Unfortunately, the acting mechanism of non-conducting oxide dopants with high chemical stability on the sulfide electrolyte has not been elucidated clearly. In this work, the rare-earth oxide La2O3 with high chemical stability was selected as a doping component of Li3PS4 sulfide electrolyte for the first time. The experimental results show that a certain amount of La2O3 can not only increase the ionic conductivity of Li3PS4 electrolyte, but also enhance their interfacial stability with the electrodes effectively. The XPS analytical results reveal the enhanced stability of Li3PS4 electrolyte with La2O3 doping due to the formation of SEI film on the lithium anode. Both the static and dynamic simulations illustrate that La2O3 particles inside the Li3PS4 electrolyte could facilitate the migration of Li+ ion by way of the “space-charge effect.”

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30

Kar, Arik, and Amitava Patra. "Recent Advances on the Optical Properties of Eu3+ Ion in Nano-Systems." Journal of Nanoscience and Nanotechnology 18, no. 12 (December 1, 2018): 8047–69. http://dx.doi.org/10.1166/jnn.2018.16135.

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Rare-earth (RE) doped nanomaterials have already proven promising materials for advanced materials and technologies including optics, lasers, catalysts, alloys, magnets, electronics, lighting, bioanalyses, imaging etc. because of their outstanding properties such as extremely narrow emission bands, long lifetimes, large strokes shifts, photostability and absence of blinking. The efficient of RE doped phosphors is found to be controlled by tuning nonradiative relaxation pathway which eventually controls by tuning crystal phase of host, lattice vibration, concentration of dopant etc. Cross relaxation nonradiative decay due to concentration quenching can be manipulated by controlling dopant concentration. This review article highlights the optical properties of Eu3+ ion in various hosts such as fluoride, phosphate, silica, semiconductor, oxyhalide, vanadate, molybdate and tungstate because of its importance for potential applications. It is important to know how the host environment influences the radiative and nonradiative relaxation which eventually controls the overall photoluminescence properties. Of particular attention is how the optical properties of Eu3+ ion vary with changing the host environment with the anticipation that such knowledge will permit us to construct efficient nanomaterials. Finally, a tentative outlook on future advances of this research field is given.

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31

Ghoshal, Sib Krishna, N. N. Yusof, Ramli Arifin, and Asmahani Awang. "Luminescence from Erbium Doped Tellurite Glass: An Insight on Titania Nanoparticles Surface Plasmon Mediation." Solid State Phenomena 268 (October 2017): 143–47. http://dx.doi.org/10.4028/www.scientific.net/ssp.268.143.

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Weak stimulated emission cross-section of rare earth ions (REIs) as dopants inside various glass hosts are disadvantageous for practical applications and needs improvement. We determine the mechanism of Titania (TiO2) nanoparticles (TNPs) mediated Surface Plasmon Resonance (SPR) assisted modification in the spectral properties of tellurite glass doped with Erbium (Er3+) ions. Transparent and thermally stable glass samples with varying TNPs contents are synthesized using melt-quenching technique. TEM images revealed the existence of TNPs with average size ranged from 16 to 26 nm. Glass containing 0.4 mol% of TNPs displayed an enhancement in the Raman signal by a factor of 2.25, 1.83, 1.98, 1.56 and 3.58 for the bands centered at 388, 495, 673, 758, and 845 cm-1, which is attributed to the SPR assisted effects. Absorption spectra of TNPs embedded glass (devoid of erbium ions) manifested two surface plasmon (SP) bands at 552 and 580 nm. Up-conversion (UC) PL spectra showed three prominent bands centered at 525, 545, and 660 nm due to the Er3+ ion transition from the excited states to the ground state. Furthermore, glass containing 0.4 mol% of TiNPs exhibited an intensity enhancement by a factor of 30, and 28.57 (green bands) and 19.60 (red band), which are ascribed to the generation of strong local electric field mediated by SPR effect of TNPs situated in the vicinity of Er3+ ion. The presence of TNPs surface plasmon is asserted to be responsible for the alteration of the Er3+ ions absorbance and modification of the UC emission intensity. A correlation between SPR and Surface Enhance Raman Scattering (SERS) is established.

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Villarreal, Renan. "(Invited, Digital Presentation) Single-Atom Quantum Magnetism in 2D Materials." ECS Meeting Abstracts MA2022-01, no. 12 (July 7, 2022): 874. http://dx.doi.org/10.1149/ma2022-0112874mtgabs.

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With the advent of 2D materials, the playground to study spins in dilute and non-dilute phases has expanded. This is appealing for utilizing the additional degrees of freedom of electron systems such as spin and valley and, from the fundamental point of view, to better understand atomic scale magnetic phenomena in low dimensional materials. Dilute magnetism in 2D materials can lead to complex magnetic phenomena (e.g., Kondo effect, RKKY-interactions, quantum relaxation and coherence), with potential for applications in spintronics (e.g., spin FETs) and quantum technologies (e.g., single-atom quantum memories). We are investigating how to selectively incorporate substitutional magnetic atoms (3d transition metals and 4f rare earths) in 2D materials, using ultra low energy ion implantation, and we characterize their structural, electronic, and magnetic properties [1]. Ultra-low energy (ULE) ion implantation allows us to precisely tune the kinetic energy of the ions, providing control over the form of incorporation and concentration while preserving the structural and electronic properties of graphene. Our approach is based on a wide range of characterization techniques (structural and electronic), including scanning tunneling microscopy and spectroscopy (STM/STS), Raman spectroscopy, synchrotron-based X-ray photoelectron spectroscopy (XPS), angle-resolved photoemission spectroscopy (ARPES), X-ray magnetic circular dichroism (XMCD), among others. These experimental studies are complemented by density functional theory (DFT) and molecular dynamics (MD) simulations. The new insights provided by our work establish a framework for the controlled incorporation of magnetic dopants in 2D materials, using ULE ion implantation. [1] P. C. Lin et al., ACS Nano 15(3), 5449-5458 (2021).

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33

Zhao, Min Shou, and Li Zhang. "Rare Earth Element Aliovalent Doping Substitution and Electrochemical Performance of LiFe_1-x Nd_xPO₄." Materials Science Forum 654-656 (June 2010): 2883–86. http://dx.doi.org/10.4028/www.scientific.net/msf.654-656.2883.

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LiFe1-xNdxPO4 /C cathode material has been synthesized by solid-state reaction. The structure and electrochemical performances of LiFe1-xNdxPO4 /C(x = 0 - 0.08) have been studied by XRD, FE-SEM, EIS and galvanostatic charge-discharge. The magnetization curve of LiFe1-xNdxPO4/C sample is measured by SQUID (Superconducting Quantum Interference Device) to examine if Fe3+ ion exists in LiFe1-xNdxPO4/C. The results show that a small amount of aliovalent Nd3+-dopant substitution on Fe+2 can effectively reduce the particle size of LiFePO4/C. The cell parameters of LiFe1-xNdxPO4 (x = 0.04 - 0.08) are calculated on Si internal standard, and LiFe1-xNdxPO4/C has the same olivine structure as LiFePO4, and delivers the highest discharge capacity of 165.2 mAh•g−1 at 0.2 C rate and the capacity retention rate is 92.8 % after 100 cycles. The charge transfer resistance decreases with adding glucose and Nd3+ ion. The measured theoretical capacity of 168.65 mAh∙g-1 is obtained. All the results imply that aliovalent doping substitution on Fe site in LiFePO4 is tolerant.

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Huang, Bolong. "Native Point Defects in CaS: Focus on Intrinsic Defects and Rare Earth Ion Dopant Levels for Up-converted Persistent Luminescence." Inorganic Chemistry 54, no. 23 (November 23, 2015): 11423–40. http://dx.doi.org/10.1021/acs.inorgchem.5b02061.

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35

Edwards, Paul, Kevin O’Donnell, Akhilesh Singh, Douglas Cameron, Katharina Lorenz, Mitsuo Yamaga, Jacob Leach, Menno Kappers, and Michal Boćkowski. "Hysteretic Photochromic Switching (HPS) in Doubly Doped GaN(Mg):Eu—A Summary of Recent Results." Materials 11, no. 10 (September 22, 2018): 1800. http://dx.doi.org/10.3390/ma11101800.

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Europium is the most-studied and least-well-understood rare earth ion (REI) dopant in GaN. While attempting to increase the efficiency of red GaN light-emitting diodes (LEDs) by implanting Eu+ into p-type GaN templates, the Strathclyde University group, in collaboration with IST Lisbon and Unipress Warsaw, discovered hysteretic photochromic switching (HPS) in the photoluminescence spectrum of doubly doped GaN(Mg):Eu. Our recent work, summarised in this contribution, has used time-, temperature- and light-induced changes in the Eu intra-4f shell emission spectrum to deduce the microscopic nature of the Mg-Eu defects that form in this material. As well as shedding light on the Mg acceptor in GaN, we propose a possible role for these emission centres in quantum information and computing.

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36

Norman, Daniel S., Farhan Azeem, Jevon J. Longdell, and Harald G. L. Schwefel. "Measuring optical loss in yttrium orthosilicate using a whispering gallery mode resonator." Materials for Quantum Technology 2, no. 1 (February 7, 2022): 011001. http://dx.doi.org/10.1088/2633-4356/ac4c39.

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Abstract The fabrication of a yttrium orthosilicate (YSO) whispering gallery mode (WGM) resonator is described, displaying quality (Q)-factors as high as 1.1 × 109. An overview of the experimental setup is presented including the procedure for spatial and spectral characterisation of the WGMs. We consider the optical losses present in such a resonator and what steps were taken in order to minimise these losses. The surface scattering in such a resonator is considered and we show that in the wavelength range of 1.5 μm, the Q-factor is not limited by scattering losses for the case in which surface inhomogeneities are weakly correlated. The high Q-factors we demonstrate have implications for rare earth ion dopant based quantum technologies because YSO is an important host material for these applications.

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37

Nagarajan, C., S. Monesh Kumar, R. Annie Sujatha, K. Mani Rahulan, and Angeline Little Flower. "Effect of annealing on the structural and optical properties of pristine and cerium doped calcium tungstate nanoparticles synthesized via hydrothermal method." IOP Conference Series: Materials Science and Engineering 1219, no. 1 (January 1, 2022): 012008. http://dx.doi.org/10.1088/1757-899x/1219/1/012008.

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Abstract The work is an investigation of the effect of annealing temperature on pristine and rare earth doped CaWO4 nanoparticles with hydrothermal route. The sample was annealed at two varied temperatures 800 ºC and 1200 ºC for 5 h. The structural analysis reveals the reduction in the broadening of the peaks as a result of annealing. Surface morphology shows the formation of agglomerated structures. In Ce3+:CaWO4 nanoparticles the morphology is modified to dumbbell like and flake like structures after annealing. Raman shift observed at 909 cm−1 Ag modes confirms the presence of CaWO4 nanoparticles with its own rotational and vibrationalmodes. Increase in the absorption peak intensity and a double absorption edge appears as an intermediate energy level state after the inclusion of Ce3+ ion as dopant.

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Murthy, K. V. R., K. Suresh, B. Nageswara Rao, B. Walter Ratna Kumar, Ch Atchyutha Rao, B. N. Rajasekhar, B. Subba Rao, and N. V. Poornachandra Rao. "Synthesis and Characterization of Sr2CeO4 Phosphor Doped with Erbium." Eurasian Chemico-Technological Journal 13, no. 1-2 (December 21, 2010): 17. http://dx.doi.org/10.18321/ectj60.

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The present paper reports the Photoluminescence (PL) of the Sr2CeO4 phosphor, singly doped with Erbium rare-earth ion with different concentrations (0.01, 0.1, 0.2, 0.5 and 1%).The phosphor samples were synthesized using the standard solid state reaction technique. The effect of Er dopant on the structural, morphological, and Photoluminescent properties of the samples are studied with X-ray diffraction (XRD), PL and SEM analysis. The PL emission of undoped Sr2CeO4 phosphor was observed at 470 nm with high intensity followed by the primary Er emissions with good intensity at 525, 530, 549, 557 and 565 nm.

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39

Hasim, Nurhafizah, Md Supar Rohani, and Md Rahim Sahar. "Structural Characteristics of Er³⁺ and Nd³⁺ Doped Lithium Niobate Tellurite Glass." Materials Science Forum 846 (March 2016): 126–30. http://dx.doi.org/10.4028/www.scientific.net/msf.846.126.

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Optimizing the rare earth doping in inorganic binary glasses for tuneable structural and optical properties is ever-demanding for lasing glass. A series of Er3+ and Nd3+ doped lithium niobate tellurite glasses with compositions of (70-x-y)TeO2–15Li2CO3–15Nb2O5–(x)Er2O3–(y)Nd2O3, where x = 0.0, 1.0 mol % and 0 ≤ y ≤ 1.0 mol% are synthesized using melt-quench technique. Influence of Nd3+ ion concentrations on physical and optical behaviour is examined. X–Ray diffraction pattern confirm the amorphous nature of glasses. The strong dependence of spectral properties on rare-earth dopant indicates the alteration in structures and bonding of glass network. The structural properties of the glass represented by the FTIR spectrum indicate that as Nd2O3 content increases, the sharp infrared absorption peaks are shifted from 474.7 cm-1 to 499.4 cm-1. These peaks are due to Nb-O, Te-O-Te and O-Te-O bond linkage bending vibrations. For TeO4 trigonal bipyramid, the peak occurred at 676.5 cm-1 whereas for TeO3 trigonal pyramid, two infrared band peaks are found at 787.5 cm-1 and 887.6cm-1, respectively. The absorption peaks around 1382.7 cm-1 is due to the Te – O – Nb stretching vibration while peaks at 1635.5cm-1 and 3411.7 cm-1 are due to the stretching vibrations of the hydroxyl group participating in the strong metal bonding as well as in the hydrogen bonding, respectively.

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40

Yokokawa, Harumi, Natsuko Sakai, Teruhisa Horita, Katsuhiko Yamaji, and M. E. Brito. "Electrolytes for Solid-Oxide Fuel Cells." MRS Bulletin 30, no. 8 (August 2005): 591–95. http://dx.doi.org/10.1557/mrs2005.166.

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AbstractThree solid-oxide fuel cell (SOFC) electrolytes, yttria-stabilized zirconia (YSZ), rare-earth–doped ceria (REDC), and lanthanum strontium gallium magnesium oxide (LSGM), are reviewed on their electrical properties, materials compatibility, and mass transport properties in relation to their use in SOFCs. For the fluorite-type oxides (zirconia and ceria), electrical properties and thermodynamic stability are discussed in relation to their valence stability and the size of the host and dopant ions. Materials compatibility with electrodes is examined in terms of physicochemical features and their relationship to the electrochemical reactions. The application of secondary ion mass spectrometry (SIMS) to detect interface reactivity is demonstrated. The usefulness of doped ceria is discussed as an interlayer to prevent chemical reactions at the electrode–electrolyte interfaces and also as an oxide component in Ni–cermet anodes to avoid carbon deposition on nickel surfaces. Finally, the importance of cation diffusivity in LSGM is discussed, with an emphasis on the grain-boundary effects.

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Raharjo, Jarot, Damisih, Masmui, Ade Utami Hapsari, Asep Riswoko, Mochamad Setyadji, Suyanti, and Maria Veronica Purwani. "Effect of the Rare Earth Oxide Impurities on the Physical and Thermal Properties of Ce_0.9Gd_0.1O_0.195 (GDC) Composite Electrolyte IT-SOFC." Materials Science Forum 929 (August 2018): 116–20. http://dx.doi.org/10.4028/www.scientific.net/msf.929.116.

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Observation on the effects of rare earth impurities on the properties of Ce0.9Gd0.1O0.195 (GDC) composite electrolyte has been performed. Indonesia has abundant rare earth elements especially CeO2, which one of the resources is from monazite mineral. In this study, the GDC powders were synthesized via solid state technique. The two types of precursors were prepared and mixed into planetary ballmill, i.e., CeO2 (Sigma Aldrich) with Gd2O3 (Sigma Aldrich) and CeO2 (non-commercial, local product) with Gd2O3 (Sigma Aldrich), namely GDC commercial and GDC non-commercial, respectively. The composite electrolyte powders calcined at temperature of 800°C in the air atmosphere condition. The composite electrolytes were then characterized in terms of its morphology, elemental, phase structure and thermal properties of the powders. The GDC commercial and non-commercial powders both consist of face centered cubic fluorite ceria structure which was confirmed by X-Ray Diffraction (XRD). The peaks are matching well with the cerium oxide JCPDS card No: 34-394. There are no peaks detected for the gadolinium oxide. It indicates that the dopant ion is fully substituted into the CeO2 lattice. The elemental analysis was performed using X-ray Fluorescence (XRF). The microstructures were observed under Scanning Electron Microscopy (SEM). The thermal properties characterizations were performed by using Thermal Gravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) from room temperature to 1500°C. Both powders investigated are suitable for electrolyte IT-SOFC based on their physical and thermal characterization. Among the composite electrolytes investigated, the GDC commercial showed the better performance in terms of their physical and thermal properties.

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Amaral, João S., Mário S. Reis, João P. Araújo, Tânia M. Mendonça, Pedro B. Tavares, Vitor S. Amaral, and Joaquim M. Vieira. "Phase Separation of La_0.70-xEr_xSr_0.30MnO₃ and its Effect on Magnetic and Magnetocaloric Properties." Materials Science Forum 587-588 (June 2008): 338–42. http://dx.doi.org/10.4028/www.scientific.net/msf.587-588.338.

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Manganites of general formula ABMnO3 (where A is a trivalent rare-earth ion and B is a divalent dopant) have interesting properties, namely colossal magnetoresistance and their applicability as materials for active magnetic regenerators. La0.70Sr0.30MnO3 (LSMO) is a ferromagnet presenting considerable magnetocaloric effect, with operating temperature TC ~ 370 K and magnetic entropy variation comparable to pure Gadolinium. The high value of TC makes LSMO unsuitable for room-temperature magnetic refrigeration applications, but by substituting La with the high-magnetic moment ion Er, TC is lowered and total magnetic entropy increases. We have found a limit of solid solubility of Er ions in LSMO, in samples prepared by either solid state or sol-gel techniques in previous works [1], in accordance with other authors [2]. We now present a more detailed study of this limit of solubility, with more samples prepared with Er substitution close to the solubility limit and SEM microscopy clearly showing the changes in microstructure caused by the formation of a secondary ErMnO3 phase, in accordance with x-ray diffraction data and TC variation along the series. The magnetocaloric properties of the series are also presented, showing the increase of Relative Cooling Power along the series, in applied magnetic fields up to 1 T.

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Vazquez-Flores, N., E. R. Vázquez-Cerón, M. Osorio-Valero, D. Nolasco-Altamirano, A. A. Barrera-Angeles, and T. Rivera-Montalvo. "Thermoluminescent response of LaAlO₃:Pr³⁺ under X-ray beams effect." Journal of Physics: Conference Series 2307, no. 1 (September 1, 2022): 012046. http://dx.doi.org/10.1088/1742-6596/2307/1/012046.

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Abstract Thermoluminescent (TL) dosimeters are the most used, since they can store information, due to exposure to radiation. Rare earth doped lanthanum aluminate (LaAlO3) ceramic has attracted great attention in recent years for many applications because it shows excellent properties such as thermal stability, color light emission as well as high thermoluminescent intensity. In the present work, TL glow curve under diagnostic X-ray beam was obtained. According to the literature, procedures in interventional cardiology are Thermoluminescent glow curve was analyzed using a Harshaw 3500 TL reader coupled to a personal computer for storage information and future analysis. For irradiation processes was used a diagnostic X-ray source Siemens 256-slice computed tomography (CT) Somaton drive model. TL response of trivalent praseodymium doped lanthanum aluminate as a function of dopant concentration was increasing as concentrations of Pr3+ ion in LaAlO3 was increased. The increase in TL glow peak sensitivity was increased up to 2 % concentration of Pr3+ ion. This TL glow curve exhibited a broad peak centered at 190°C and little shoulder which is consider as the second peak centered at 260°C respectively. The nature of the glow curve form in samples is attributed to at least one type of the trap with relates at least one type of the defect. After experimental results LaAlO3:Pr3+ can be used as thermoluminescent material for diagnostic X-ray beams measurements.

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Santos, S. C., O. Rodrigues, and L. L. Campos. "Synthesis, processing and electron paramagnetic resonance response of Y1.98Eu0.02O3 micro rods." International Journal of Modern Physics: Conference Series 48 (January 2018): 1860112. http://dx.doi.org/10.1142/s2010194518601126.

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Innovating dosimetric materials, which includes design and development of new dosimetric materials based on rare earth oxides, is challenging. Yttrium oxide (Y[Formula: see text]O[Formula: see text] is one of the most important sesquioxides and presents crystal characteristics that enable doping with rare earth ions, making it a promising material for radiation dosimetry. This paper reports on the development and measurement of Electron Paramagnetic Resonance (EPR) signal response for Y[Formula: see text]Eu[Formula: see text]O[Formula: see text][Formula: see text]micro rods that have undergone facile low-pressure hydrothermal synthesis and bio-prototyping. As- synthesized powders with narrow sub-micrometer particle size distribution with d[Formula: see text][Formula: see text] of 584 nm exhibited a reactive surface, which led to the formation of stable aqueous suspensions by controlling the surface charge density of particles through alkaline pH adjustment. Ceramic samples with dense microstructure were formed by sintering at 1600 [Formula: see text]C for 4h at ambient atmosphere. Y[Formula: see text]Eu[Formula: see text]O[Formula: see text][Formula: see text]micro rods were irradiated using a [Formula: see text]Co source with doses from 1 to 100 kGy, and EPR spectra were measured at room temperature in X-band microwave frequencies. Sintered samples exhibited linearity of the main EPR signal response from 10 Gy to 10 kGy. Supralinearity was observed for higher doses, which is possibly ascribed to formation of more defects. Using europium as a dopant enhanced the EPR signal of yttrium rods remarkably, due to 4f–4f transitions of the Eu[Formula: see text] ion. These innovative findings make europium-doped yttrium oxide a promising material for radiation dosimetry.

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Zhang, Xinyi, Kuankuan Lu, Zhuohui Xu, Honglong Ning, Zimian Lin, Tian Qiu, Zhao Yang, Xuan Zeng, Rihui Yao, and Junbiao Peng. "Amorphous NdIZO Thin Film Transistors with Contact-Resistance-Adjustable Cu S/D Electrodes." Membranes 11, no. 5 (April 30, 2021): 337. http://dx.doi.org/10.3390/membranes11050337.

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High-performance amorphous oxide semiconductor thin film transistors (AOS-TFT) with copper (Cu) electrodes are of great significance for next-generation large-size, high-refresh rate and high-resolution panel display technology. In this work, using rare earth dopant, neodymium-doped indium-zinc-oxide (NdIZO) film was optimized as the active layer of TFT with Cu source and drain (S/D) electrodes. Under the guidance of the Taguchi orthogonal design method from Minitab software, the semiconductor characteristics were evaluated by microwave photoconductivity decay (μ-PCD) measurement. The results show that moderate oxygen concentration (~5%), low sputtering pressure (≤5 mTorr) and annealing temperature (≤300 °C) are conducive to reducing the shallow localized states of NdIZO film. The optimized annealing temperature of this device configuration is as low as 250 °C, and the contact resistance (RC) is modulated by gate voltage (VG) instead of a constant value when annealed at 300 °C. It is believed that the adjustable RC with VG is the key to keeping both high mobility and compensation of the threshold voltage (Vth). The optimal device performance was obtained at 250 °C with an Ion/Ioff ratio of 2.89 × 107, a saturation mobility (μsat) of 24.48 cm2/(V·s) and Vth of 2.32 V.

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Rani, Suman, Bansi Lal, Sumit Saxena, and Shobha Shukla. "Modifications in the Structural and Optical Properties of ZnO Nanophosphor on Doping with Tb." Nanoscience & Nanotechnology-Asia 9, no. 3 (September 4, 2019): 353–61. http://dx.doi.org/10.2174/2210681208666180221123044.

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Background: The characteristic visible emission from ZnO being attributed to the defect energy states can be tailored by doping as well as by synthesis techniques. Rare-earth elements, among various dopants, are interesting because of their unique emission properties in the visible region. Terbium (Tb), in particular, is reported to contribute significantly to the creation of the defect energy states when doped in ZnO. This study investigated the Tb concentration dependent modifications in the structural and optical properties of ZnO nanophosphor. Methods: Tb (0.1, 0.5, 01.0 mol%) doped nanophosphor powder samples prepared by low temperature precipitation method, were sintered in air at 700oC using a home-built temperature controlled (±1oC) muffle furnace. Powder XRD and EDX spectra at room temperature were recorded using Philips X perts x-ray spectrometer while Jeol JSM-7600F was used to record SEM images. Photoluminescence spectra excited by the 280, 300, 380 and 460nm radiation from a Xe lamp were recorded using Carry 8000 spectrophotometer. Raman spectra excited by 514.5nm radiation from an Ar-ion laser, was investigated using Morrison microscope Olympus Bx 41 while UV-VIS absorption spectra were recorded on UV- 1800 UV-VIS Spectrophotometer. Results: FTIR and XRD spectra showed that the basic ZnO wurtzite crystal structure remained unchanged on doping. However, XRD data analysis indicated that the 0.1 mol% Tb might be incorporated in ZnO unit cell at an interstitial and / or substitutional site(s) while at 0.5 and 1.0 mol% doping levels migration of Tb to the surface could be the dominant process. This was further confirmed by Raman and photoluminescence studies. Broad emission (122nm FWHM) peaking around 510nm was observed when the doped samples were excited with 280 and 300nm radiation while characteristic ZnO emission was observed with 380 and 460nm radiation. The calculated chromaticity color coordinates (x,y) of the emission excited by 280nm in 0.5 mol% doped ZnO were: x=0.29 and y=0.31, which are very close to those of the daylight at noon. Conclusion: Concentration dependent lattice distortions were observed; it was concluded that at 0.1mol% concentration level Tb was incorporated in ZnO lattice resulting in interstitial or substitutional defects. On the other hand, at 0.5 and 1.0 mol% doping levels diffusion of Tb to the surface producing strain due to "hydrostatic like pressure" seemed to be the dominating process; maximum strain was observed at 0.5mol% doping. The calculated chromaticity color coordinates of the 280nm excited emission from ZnO:Tb (0.5mol%) were found to be very close to those of the "day light at noon” indicating the suitability of the material for the realization of white light sources.

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47

Jackson, R. A., M. E. G. Valerio, and J. F. de Lima. "Computer modelling of rare-earth dopants in BaLiF3." Journal of Physics: Condensed Matter 13, no. 10 (February 22, 2001): 2147–54. http://dx.doi.org/10.1088/0953-8984/13/10/309.

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Tachibana, Makoto, Akio Iwanade, and Kokoro Miyakawa. "Distribution coefficient of rare-earth dopants in Y3Al5O12 garnet." Journal of Crystal Growth 568-569 (August 2021): 126191. http://dx.doi.org/10.1016/j.jcrysgro.2021.126191.

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49

Moriwake, Hiroki, Craig A. J. Fisher, and Akihide Kuwabara. "First-Principles Calculations of Rare-Earth Dopants in BaTiO3." Japanese Journal of Applied Physics 48, no. 9 (September 24, 2009): 09KC03. http://dx.doi.org/10.1143/jjap.48.09kc03.

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Filhol, J. S., R. Jones, M. J. Shaw, and P. R. Briddon. "Structure and electrical activity of rare-earth dopants in GaN." Applied Physics Letters 84, no. 15 (April 12, 2004): 2841–43. http://dx.doi.org/10.1063/1.1710710.

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Journal articles on the topic 'Rare earth ion dopants'

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