Journal articles: 'Local Conductivity Probe'

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HASEGAWA, SHUJI, ICHIRO SHIRAKI, FUHITO TANABE, REI HOBARA, TAIZO KANAGAWA, TAKEHIRO TANIKAWA, IWAO MATSUDA, et al. "ELECTRICAL CONDUCTION THROUGH SURFACE SUPERSTRUCTURES MEASURED BY MICROSCOPIC FOUR-POINT PROBES." Surface Review and Letters 10, no. 06 (December 2003): 963–80. http://dx.doi.org/10.1142/s0218625x03005736.

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For in-situ measurements of the local electrical conductivity of well-defined crystal surfaces in ultrahigh vacuum, we have developed two kinds of microscopic four-point probe methods. One involves a "four-tip STM prober," in which four independently driven tips of a scanning tunneling microscope (STM) are used for measurements of four-point probe conductivity. The probe spacing can be changed from 500 nm to 1 mm. The other method involves monolithic micro-four-point probes, fabricated on silicon chips, whose probe spacing is fixed around several μm. These probes are installed in scanning-electron-microscopy/electron-diffraction chambers, in which the structures of sample surfaces and probe positions are observed in situ. The probes can be positioned precisely on aimed areas on the sample with the aid of piezoactuators. By the use of these machines, the surface sensitivity in conductivity measurements has been greatly enhanced compared with the macroscopic four-point probe method. Then the conduction through the topmost atomic layers (surface-state conductivity) and the influence of atomic steps on conductivity can be directly measured.

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Kalinin, Sergei. "Measuring Conductivity With Scanning Probe Microscopes." Microscopy Today 10, no. 2 (March 2002): 26–27. http://dx.doi.org/10.1017/s1551929500057837.

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There are two kinds of conductivity measurements possible with scanning probe microscopy (SPM). In the first case, the specific resistance of material directly below the tip is probed. In the second case, SPM probes local potential induced by the lateral current applied through macroscopic contacts, thus providing the information on the mesoscopic transport properties of the sample.The first set of techniques is invariably based on measuring tip-surface current in contact or intermittent tapping mode. If the tip-surface contact resistance is small (good contact), the current will be limited by the spreading resistance of the sample from which specific resistance can be calculated, assuming that the contact area is known.

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JU, BING-FENG, YANG JU, and MASUMI SAKA. "NOVEL AFM PROBE FOR LOCAL CONDUCTIVITY MEASUREMENT." International Journal of Nanoscience 05, no. 04n05 (August 2006): 413–18. http://dx.doi.org/10.1142/s0219581x06004565.

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A new atomic force microscope (AFM) probe for local conductivity measurement is presented. This silicon nitride based probe with a V-shaped two-dimensional sliced structure tip is patterned by using conventional photolithography method. The probe is then etched to four parallel electrodes that isolated from each other, for the purpose of performing current input and electrical potential drop measurement. The newly developed four-point AFM probe not only inherits the function of AFM surface topography generating but also has the capability of characterizing the local conductivity simultaneously. The nanoresolution position control mechanism of AFM allows the probe scanning across micrometers sized area and creating high spatial resolution map of the in-plane conductivities. Experiments have shown this four-point AFM probe to be mechanically flexible and robust. The repeatable conductivity measurements on the surface of aluminum and indium tin oxide (ITO) thin films indicate this four-point AFM probe technique has potential applications for characterizing devices and materials in microscale.

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SHIRAKI, ICHIRO, TADAAKI NAGAO, SHUJI HASEGAWA, CHRISTIAN L. PETERSEN, PETER BØGGILD, TORBEN M. HANSEN, and FRANÇOIS HANSEN. "MICRO-FOUR-POINT PROBES IN A UHV SCANNING ELECTRON MICROSCOPE FOR IN-SITU SURFACE-CONDUCTIVITY MEASUREMENTS." Surface Review and Letters 07, no. 05n06 (October 2000): 533–37. http://dx.doi.org/10.1142/s0218625x00000592.

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For in-situ measurements of surface conductivity in ultrahigh vacuum (UHV), we have installed micro-four-point probes (probe spacings down to 4 μm) in a UHV scanning electron microscope (SEM) combined with scanning reflection–high-energy electron diffraction (RHEED). With the aid of piezoactuators for precise positioning of the probes, local conductivity of selected surface domains of well-defined superstructures could be measured during SEM and RHEED observations. It was found that the surface sensitivity of the conductivity measurements was enhanced by reducing the probe spacing, enabling the unambiguous detection of surface-state conductivity and the influence of surface defects on the electrical conduction.

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García Cantú, Rigoberto. "Scanning tunneling microscope as a probe for local conductivity." Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures 9, no. 2 (March 1991): 670. http://dx.doi.org/10.1116/1.585528.

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Bordusau, S., S. Madveika, and A. Dostanko. "Investigation of Microwave Energy Distribution Character in a Resonator Type Plasmatron." PLASMA PHYSICS AND TECHNOLOGY 3, no. 3 (February 14, 2016): 122–25. http://dx.doi.org/10.14311/ppt.2016.3.122.

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An investigation of microwave energy distribution character in a plasma of microwave discharge inside a plasmatron based on a rectangular resonator has been carried out. The experiments were done applying the "active probe" method. Microwave discharge was excited in the air and oxygen. It has been found out that the readings of the "active probe" along the discharge chamber are of periodic character. The readings of the "active probe" and data on the local electric conductivity of plasma obtained using electrical probes have been compared.

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Barnett, C. J., O. Kryvchenkova, L. S. J. Wilson, T. G. G. Maffeis, K. Kalna, and R. J. Cobley. "The role of probe oxide in local surface conductivity measurements." Journal of Applied Physics 117, no. 17 (May 7, 2015): 174306. http://dx.doi.org/10.1063/1.4919662.

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Nasr-El-Din, H., C. A. Shook, and J. Colwell. "A conductivity probe for measuring local concentrations in slurry systems." International Journal of Multiphase Flow 13, no. 3 (May 1987): 365–78. http://dx.doi.org/10.1016/0301-9322(87)90055-3.

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Lee, Jong Sub, Gye Chun Cho, and Eun Soo Hong. "High Resolution Electrical Resistance Profiling of Laboratory Soil Specimens." Key Engineering Materials 321-323 (October 2006): 1399–402. http://dx.doi.org/10.4028/www.scientific.net/kem.321-323.1399.

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An electrical needle-size probe is developed to effectively assess one-dimensional spatial variability of laboratory soil specimens in high resolution. A calibration procedure is also presented to determine resistance from the measured complex impedance. The capability of the developed electrical needle probes to resolve interfaces and spatial variability is explored using sand specimens prepared by various conditions. The complex impedance is measured 0.2~0.5 mm for every specimen. Results show that the coefficient of variation increases as the size of the probe reaches the size of the particle while a very large ratio of probe size to grain size would decrease the detectability of local soil variations due to averaging effects and smoothening. The attainable spatial resolution depends on the needle diameter: submillimetric resolution is typically achieved in laboratory applications and it can be scaled for field applications. The local electrical parameters permit one to infer the soil porosity and the electrolyte conductivity.

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Fujimoto, A., L. Zhang, A. Hosoi, and Y. Ju. "Structure modification of M-AFM probe for the measurement of local conductivity." Microsystem Technologies 17, no. 4 (December 9, 2010): 715–20. http://dx.doi.org/10.1007/s00542-010-1175-9.

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Li, Hong Li, Yang Dong Li, and Deng Xin Li. "Influence of Superficial Gas Velocity on the Dynamic Characteristics Parameters of CFB." Advanced Materials Research 663 (February 2013): 953–57. http://dx.doi.org/10.4028/www.scientific.net/amr.663.953.

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The effects of superficial gas velocity (Ug) on the dynamic characteristics parameters (electrical conductivity, local phase holdup and minimum fluidization velocity (Ugmf)) of CFB were examined by the conductivity probe method. Experimental results show effects of Ug on electrical conductivity, local phase holdups and Ugmf are rather obvious. In radial direction, the further to gas distribution board, with Ug increased bubble distribution was more uniform, radial distribution of electrical conductivity was more uniform. When Ug increases, electrical conductivity increases, distribution of it is uneven. From test hole 2 upward, electrical conductivity decreases in different axial direction. With the increase of Ug, local gas phase (g) also increases gradually, local solid phase (s) also increases gradually, and at different region, its amplitude is different. When value of Ug is small, fluidized bed belongs to the fixed bed, and with the increase of Ug, glass particles suspend slowly to fluidized state. Simultaneously, Ugmf is greatly affected by particle content and particle size.

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Ivanov, Maxim S., Vladimir A. Khomchenko, Maxim V. Silibin, Dmitry V. Karpinsky, Carsten Blawert, Maria Serdechnova, and José A. Paixão. "Investigation of Local Conduction Mechanisms in Ca and Ti-Doped BiFeO3 Using Scanning Probe Microscopy Approach." Nanomaterials 10, no. 5 (May 14, 2020): 940. http://dx.doi.org/10.3390/nano10050940.

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In this work we demonstrate the role of grain boundaries and domain walls in the local transport properties of n- and p-doped bismuth ferrites, including the influence of these singularities on the space charge imbalance of the energy band structure. This is mainly due to the charge accumulation at domain walls, which is recognized as the main mechanism responsible for the electrical conductivity in polar thin films and single crystals, while there is an obvious gap in the understanding of the precise mechanism of conductivity in ferroelectric ceramics. The conductivity of the Bi0.95Ca0.05Fe1−xTixO3−δ (x = 0, 0.05, 0.1; δ = (0.05 − x)/2) samples was studied using a scanning probe microscopy approach at the nanoscale level as a function of bias voltage and chemical composition. The obtained results reveal a distinct correlation between electrical properties and the type of charged defects when the anion-deficient (x = 0) compound exhibits a three order of magnitude increase in conductivity as compared with the charge-balanced (x = 0.05) and cation-deficient (x = 0.1) samples, which is well described within the band diagram representation. The data provide an approach to control the transport properties of multiferroic bismuth ferrites through aliovalent chemical substitution.

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JU, Yang, and Masumi SAKA. "Measurement of Local Electrical Conductivity by Four-Point Probe Atomic Force Microscope Technique." Journal of the Society of Materials Science, Japan 56, no. 10 (2007): 896–99. http://dx.doi.org/10.2472/jsms.56.896.

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Ju, Yang, Bing-Feng Ju, and Masumi Saka. "Microscopic four-point atomic force microscope probe technique for local electrical conductivity measurement." Review of Scientific Instruments 76, no. 8 (August 2005): 086101. http://dx.doi.org/10.1063/1.1988130.

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MacTaggart, R. S., H. A. Nasr-El-Din, and J. H. Masliyah. "A conductivity probe for measuring local solids concentration in a slurry muxing tank." Separations Technology 3, no. 3 (July 1993): 151–60. http://dx.doi.org/10.1016/0956-9618(93)80015-j.

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Liu, Baichuan, Nicole James, Dean Wheeler, and Brian A. Mazzeo. "Effect of Calendering on Local Ionic and Electronic Transport of Porus Electrodes." ECS Meeting Abstracts MA2022-02, no. 6 (October 9, 2022): 612. http://dx.doi.org/10.1149/ma2022-026612mtgabs.

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The microstructure determines transport properties in lithium-ion battery electrodes. There is generally a tradeoff between electronic and ionic transport when adjusting the microstructure. One way of adjusting the microstructure is through calendering, where the electrode is compressed following drying. Understanding how calendering affects not only the average but also the local electronic and ionic transport provides additional insight when developing battery electrodes and engineering better batteries. If a correlation exists between the two properties, an optimal porosity that maximizes both ionic and electronic transport could be determined. In order to better understand the influence of microstructure on these transport properties, we tested a series of commercial-grade electrodes including NMC cathodes, graphite anodes, and a graphite-silicon anode. The local electronic conductivity of the electrodes was found using a micro-flexible-surface probe previously developed by our research group [1]. Likewise, the local ionic conductivity was found using an aperture probe previously developed by our research group [2]. All electrodes were obtained from Argonne National Laboratory in calendered and un-calendered states. Through testing various electrodes before and after calendering, we found that not every electrode experienced an increase in electronic conductivity after calendering, and that in general heterogeneity of the electronic conductivity decreased after calendering. The local ionic resistance, as indicated by MacMullin number, was found to increase after calendering, as expected. Figure 1 illustrates the local ionic and electronic transport results for one cathode. Ionic transport was found to be almost solely influenced by porosity. However, electronic transport was found to be influenced by a variety of factors including the nature, distribution, and connectivity of conductive materials. [1] Vogel et al., J. Electrochem. Soc. 168, 100504 (2021). [2] Liu et al., ECS Meeting Abstracts 2021, 444. Figure 1

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Zhang, Junping, Norman Epstein, John R. Grace, and Kokseng Lim. "Bubble Characteristics in a Developing Vertical Gas–Liquid Upflow Using a Conductivity Probe." Journal of Fluids Engineering 122, no. 1 (October 12, 1999): 138–45. http://dx.doi.org/10.1115/1.483250.

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Experiments were carried out in an 82.6-mm-dia column with a perforated distributor plate. Conductivity probes on the axis of the column were used to measure local bubble properties in the developing flow region for superficial air velocities from 0.0018 to 6.8 m/s and superficial water velocities from 0 to 0.4 m/s, corresponding to the discrete bubble, dispersed bubble, coalesced bubble, slug, churn, bridging, and annular flow regimes. Bubble frequency increased linearly with gas velocity in the discrete and dispersed bubble regimes. Bubble frequency also increased with gas velocity in the slug flow regime, but decreased in the churn and bridging regimes. Bubble chord length and its distribution were smaller and narrower in the dispersed than in the discrete bubble regime. Both the average and standard deviation of the bubble chord length increased with gas velocity in the discrete, dispersed, and churn flow regimes. However, the average bubble chord length did not change significantly in the slug flow regime due to the high population of small bubbles in the liquid plugs separating Taylor bubbles. The bubble travel length, defined as the product of local gas holdup and local bubble velocity divided by local bubble/void frequency, is used to correlate bubble characteristics and to characterize the flow regimes. [S0098-2202(00)00101-2]

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KROCHAK, PAUL, and LARS THOMSSON. "A new method for characterizing turbulent mixing in semiconcentrated suspensions." November 2011 11, no. 11 (December 1, 2011): 45–52. http://dx.doi.org/10.32964/tj10.11.45.

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A high-frequency conductivity probe was used in conjunction with advanced signal processing to measure the turbulent fluctuations of a passive scalar, namely a saline solution, injected into semiconcentrated, monodispersed suspensions consisting of either 2-mm rayon fibers or 130-μm microspheres. The probe was mounted in a pipe flow so that its radial position could be adjusted manually. A saline solution was injected into the centerline of the pipe at a specified velocity relative to the suspension flow. The mean conductivity signal gathered with this tool enabled estimation of the local concentration of salt at a given point in the flow, i.e., the mean spatial dispersion of the dosed component. Further analysis of the high-frequency fluctuating signal enables characterization of the local mixing energy and turbulent spectrum, i.e., the spectral mixing scales available in the suspensions under a given set of conditions.

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Goldshtein, Aleksandr E., and Vasily Y. Belyankov. "The Eddy Current Method of Alloy Drill Pipes Wall Thickness Evaluation: Impact Analysis." Materials Science Forum 970 (September 2019): 336–42. http://dx.doi.org/10.4028/www.scientific.net/msf.970.336.

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The dependences of the surface eddy current probe added voltage at the interaction of the probe magnetic field with an aluminum pipe from the following main interference factors are determined: the pipe wall thickness, the gap between the probe and the surface of the pipe, the electrical conductivity of the material, the curvature of the pipe wall, the presence of areas with a smooth thickness change of the wedge character and a local spherical thinning, axis misalignment with respect to the pipe surface, the lateral misalignment of the probe axis. The problem is solved with the help of the finite element method (FEM). These data are consistent with the experimental results.

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Huang, Yichuan, Nan Gui, Xingtuan Yang, Jiyuan Tu, Shengyao Jiang, and Hongye Zhu. "Local measurement of bubbly flow in helically coiled tubes using double-sensor conductivity probe." Journal of Nuclear Science and Technology 57, no. 6 (February 4, 2020): 689–703. http://dx.doi.org/10.1080/00223131.2020.1720846.

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Ju, Bing-Feng, Yang Ju, and Masumi Saka. "Fabrication of a microscopic four-point probe and its application to local conductivity measurement." Journal of Micromechanics and Microengineering 15, no. 12 (November 8, 2005): 2277–81. http://dx.doi.org/10.1088/0960-1317/15/12/009.

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Wang, Yu-Hsing, and Xiaobo Dong. "Laboratory characterization of the spatial variability in soils by the EM-wave-based technique." Canadian Geotechnical Journal 45, no. 1 (January 2008): 102–16. http://dx.doi.org/10.1139/t07-080.

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A slim-form, open-ended coaxial probe with an outside diameter of 2.2 mm was used in this study to take local dielectric measurements in soils. The dielectric relaxation strength of bulk water, Δκw, and the DC conductivity of the saturated sample, σmix, are jointly used to characterize the spatial variability of different specimens including glass beads, sand and mica samples, and kaolinite sediments with two different fabric associations. The pore distribution along the sample depth can be inferred from the local Δκw using mixing rules. The directional feature of the interconnected pores is captured in the tortuosity, which is derived from the measured σmix and the DC conductivity of the pore fluid σpf. In kaolinite sediments, the ratio between the sediment and the pore-fluid conductivity not only reveals the spatial variability of the sediment packing but also the relative contribution of the fluid conductivity and the surface conduction to the overall sediment conductivity.

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Nasr Esfahani, Ehsan, Feiyue Ma, Shanyu Wang, Yun Ou, Jihui Yang, and Jiangyu Li. "Quantitative nanoscale mapping of three-phase thermal conductivities in filled skutterudites via scanning thermal microscopy." National Science Review 5, no. 1 (June 30, 2017): 59–69. http://dx.doi.org/10.1093/nsr/nwx074.

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Abstract In the last two decades, a nanostructuring paradigm has been successfully applied in a wide range of thermoelectric materials, resulting in significant reduction in thermal conductivity and superior thermoelectric performance. These advances, however, have been accomplished without directly investigating the local thermoelectric properties, even though local electric current can be mapped with high spatial resolution. In fact, there still lacks an effective method that links the macroscopic thermoelectric performance to the local microstructures and properties. Here, we show that local thermal conductivity can be mapped quantitatively with good accuracy, nanometer resolution and one-to-one correspondence to the microstructure using a three-phase skutterudite as a model system. Scanning thermal microscopy combined with finite element simulations demonstrate close correlation between sample conductivity and probe resistance, enabling us to distinguish thermal conductivities spanning orders of magnitude, yet resolving thermal variation across a phase interface with small contrast. The technique thus provides a powerful tool to correlate local thermal conductivities, microstructures and macroscopic properties for nanostructured materials in general and nanostructured thermoelectrics in particular.

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Schneider, Jeffrey M., and Dante Fratta. "Time-domain reflectometry — parametric study for the evaluation of physical properties in soils." Canadian Geotechnical Journal 46, no. 7 (July 2009): 753–67. http://dx.doi.org/10.1139/t09-018.

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Time-domain reflectometry (TDR) has become a commonly used method in geotechnical engineering to measure the volumetric water content and electrical conductivity in soils. The ability of TDR to accurately determine soil properties depends on the proper understanding of the parameters that affect the propagation of an electromagnetic pulse along the TDR waveguide. The purpose of this paper is to document a parametric study and analyses aimed at gaining a better understanding of TDR measurements and to evaluate the limits in the measurement technique. A parametric study on TDR signals was performed by determining the effects of heterogeneities in the dielectric permittivity, conductivity, and magnetic permeability in sand and gravel specimens. Impedance differences in the probe head were found to contribute to inaccurate travel-time measurements that affect material dielectric permittivity calculations. The calculated relative dielectric permittivity may also be dependent on local changes in porosity near the probes. Tests performed in layered materials indicate that TDR can be used to find abrupt changes in material permittivity, such as the depth to saturation. However, problems in the determination of capillary rise may contribute to uncertainties in the proper determination of permittivity and thicknesses of layers. The presence of ferromagnetic materials was found to change the measured electromagnetic wave velocity. However, the properties of materials outside the radius defined by the probes and beneath the probes minimally affected the TDR results in the two-rod probe used.

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Saeedikhani, Mohsen, Sareh Vafakhah, and Daniel J. Blackwood. "Can Finite Element Method Obtain SVET Current Densities Closer to True Localized Corrosion Rates?" Materials 15, no. 11 (May 24, 2022): 3764. http://dx.doi.org/10.3390/ma15113764.

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In this paper, the finite element method was used to simulate the response of the scanning vibrating electrode technique (SVET) across an iron–zinc cut-edge sample in order to provide a deeper understanding of the localized corrosion rates measured using SVET. It was found that, if the diffusion layer was neglected, the simulated current density using the Laplace equation fitted the experimental SVET current density perfectly. However, the electrolyte was not perturbed by a vibrating SVET probe in the field, so a diffusion layer existed. Therefore, the SVET current densities obtained from the local conductivity of the electrolyte would likely be more representative of the true corrosion rates than the SVET current densities obtained from the bulk conductivity. To help overcome this difference between natural conditions and those imposed by the SVET experiment, a local electrolyte corrected conductivity SVET (LECC-SVET) current density was introduced, which was obtained by replacing the bulk electrolyte conductivity measured experimentally by the local electrolyte conductivity simulated using the Nernst−Einstein equation. Although the LECC-SVET current density did not fit the experimental SVET current density as perfectly as that obtained from the Laplace equation, it likely represents current densities closer to the true, unperturbed corrosion conditions than the SVET data from the bulk conductivity.

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Miller, M. K. "Atom Probe Tomography: A Tutorial." Microscopy and Microanalysis 6, S2 (August 2000): 1188–89. http://dx.doi.org/10.1017/s1431927600038435.

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Atom probe tomography (APT) is an ultrahigh resolution microanalytical technique that enables the spatial coordinates and elemental identities of the atoms in a small volume of material to be determined. The specimen volume that may be analyzed is typically ∼ 10 to 20 nm square by ∼ 100 to 250 nm deep, and contains up to ∼ 1 million atoms. The distribution of the solute atoms within this volume may then be reconstructed from these data. The compositions of small volumes are determined by simply counting the number of atoms of each type within that volume, and thus the technique provides a fundamental measure of local concentrations. Atom probe tomography requires that the specimen has some electrical conductivity and may be applied to almost all metals and alloys, many semiconductors, and some electrically conducting ceramics. The sharp needle-shaped specimens may be fabricated from bulk and thin film materials with the use of electropolishing, chemical or ion milling methods.

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Liu, Malin, Tiefeng Wang, Wei Yu, and Jinfu Wang. "An electrical conductivity probe method for measuring the local solid holdup in a slurry system." Chemical Engineering Journal 132, no. 1-3 (August 2007): 37–46. http://dx.doi.org/10.1016/j.cej.2007.01.014.

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Kalinin, Sergei V., and Dawn A. Bonnell. "Artifacts and Non-Local Effects in SPM Potential Measurements." Microscopy Today 10, no. 4 (July 2002): 16–21. http://dx.doi.org/10.1017/s1551929500058156.

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In the last few years Scanning Probe Microscopy (SPM) has become one of the primary tools of science and technology. In addition to topographical imaging, surface potential, conductivity, optical, ferroelectric and magnetic properties that can be studied down to the nanometer level. However, quantitative and sometimes qualitative studies of fundamental physical phenomena in meso- and nanoscale systems are often hindered by SPM imaging artifacts. Here we briefly discuss the principles of operation and the major sources of artifacts in electrostatic measurements by SPM.One of the most well known techniques for local potential imaging is Scanning Surface Potential Microscopy (SSPM). SSPM is based on dual pass imaging. The grounded tip acquires surface topography during the first pass.

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Sun, Xiaodong, Sidharth Paranjape, Seungjin Kim, Hiroshi Goda, Mamoru Ishii, and Joseph M. Kelly. "Local Liquid Velocity in Vertical Air-Water Downward Flow." Journal of Fluids Engineering 126, no. 4 (July 1, 2004): 539–45. http://dx.doi.org/10.1115/1.1777235.

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This paper presents an experimental study of local liquid velocity measurement in downward air-water bubbly and slug flows in a 50.8 mm inner-diameter round pipe. The axial liquid velocity and its fluctuations were measured by a laser Doppler anemometry (LDA) system. It was found that the maximum liquid velocity in a downward two-phase flow could occur off the pipe centerline at relatively low liquid flow rates and this observation is consistent with other researchers’ results. The comparisons between the liquid flow rates measured by a magnetic flow meter and those obtained from the local LDA and multi-sensor conductivity probe measurements showed good agreement. In addition, based on the local measurements the distribution parameter and the drift velocity in the drift-flux model were obtained for the current downward flow tests.

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Mannucci, A. J., B. T. Tsurutani, O. Verkhoglyadova, A. Komjathy, and X. Pi. "Use of radio occultation to probe the high latitude ionosphere." Atmospheric Measurement Techniques Discussions 8, no. 2 (February 23, 2015): 2093–121. http://dx.doi.org/10.5194/amtd-8-2093-2015.

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Abstract. We have explored the use of COSMIC data to provide valuable scientific information on the ionospheric impacts of energetic particle precipitation during geomagnetic storms. Ionospheric electron density in the E region, and hence ionospheric conductivity, is significantly altered by precipitating particles from the magnetosphere. This has global impacts on the thermosphere-ionosphere because of the important role of conductivity on high latitude Joule heating. Two high-speed stream (HSS) and two coronal mass ejection (CME) storms are examined with the COSMIC data. We find clear correlation between geomagnetic activity and electron density retrievals from COSMIC. At nighttime local times, the number of profiles with maximum electron densities in the E layer (below 200 km altitude) is well correlated with geomagnetic activity. We interpret this to mean that electron density increases due to precipitation are captured by the COSMIC profiles. These "E layer dominant ionosphere" (ELDI) profiles have geomagnetic latitudes that are consistent with climatological models of the auroral location. For the two HSS storms, that occurred in May of 2011 and 2012, a strong hemispheric asymmetry is observed, with nearly all the ELDI profiles found in the southern, less sunlit, hemisphere. Stronger aurora and precipitation have been observed before in winter hemispheres, but the degree of asymmetry deserves further study. For the two CME storms, occurring in July and November of 2012, large increases in the number of ELDI profiles are found starting in the storm's main phase but continuing for several days into the recovery phase. Analysis of the COSMIC profiles was extended to all local times for the July 2012 CME storm by relaxing the ELDI criterion and instead visually inspecting all profiles above 50° magnetic latitude for signatures of precipitation in the E region. For nine days during the July 2012 period, we find a signature of precipitation occurs nearly uniformly in local time, although the magnitude of electron density increase may vary with local time. The latitudinal extent of the precipitation layers is generally consistent with auroral climatology. However, after the storm main phase on 14 July 2012, the precipitation tended to be somewhat more equatorward than predicted by the climatology (by about 5–10° latitude). We conclude that, if analyzed appropriately, high latitude COSMIC profiles have the potential to contribute to our understanding of MI coupling processes and extend and improve existing models of the auroral region.

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Bakli, Hind, Mohamed Moualhi, and Mourad Makhlouf. "High-sensitivity electrical properties measurement of graphene-based composites using interferometric near-field microwave technique." Measurement Science and Technology 33, no. 4 (January 24, 2022): 045012. http://dx.doi.org/10.1088/1361-6501/ac3d09.

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Abstract High-sensitivity electrical properties measurement of composite materials using an interferometric near-field microwave technique is proposed in this paper. A one-port calibration model is developed to relate the measured transmission coefficient to the local properties of the material. To represent the probe–composite sample interaction, an electrical model based on lumped elements is developed. As a demonstration, the complex permittivity and conductivity of composite materials prepared with polyvinyl chloride and different concentrations of graphene are experimentally determined at 2.45 GHz. The obtained results show that the proposed technique is sensitive for the detection of small contrasts of permittivity and conductivity in the composite material. When the graphene concentration increases from 1% to 30%, the conductivity increases from 0.0061 s m−1 to 0.056 s m−1.

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Gaisky, V. A., and P. V. Gaisky. "Possibilities of measuring the local density of seawater in probe instruments." Monitoring systems of environment, no. 1 (March 25, 2021): 61–67. http://dx.doi.org/10.33075/2220-5861-2021-1-61-67.

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In modern expeditionary research carried out on research vessels, the local density of seawater is not measured, but calculated using the TEOS-10 thermodynamic equation of state based on cumulative measurements of pressure, temperature and electrical conductivity or speed of sound. The equation of state with satisfactory accuracy is valid only for oceanological waters, and is used with corrections for the waters of the marginal and inland seas. These corrections are permanently refined and will be refined in the future. It is desirable to have direct measurements of the local density of any waters directly in the environment with sufficient accuracy, which is now 4·10-6. Laboratory measurements made by various methods and with different devices, not always automated, give accuracy ~ . Attempts to automate these measurements and introduce them into sounding devices have been made several times. Experimental samples of vibration, refractometric and hydrostatic devices have been created and tested, none of which have been introduced into the practice of expeditionary work for various reasons. However, scientific and technological progress makes possible technical solutions previously difficult to implement. This also applies to modifications of the hydrostatic method for measuring the local density, which have recently attracted the interest of developers. The paper analyzes the possibilities of implementing the hydrostatic method using multi-element resistor distributed pressure and temperature sensors, resistance profilers of these sensors and determining the spatial pressure drop on a given base by measuring and subtracting sensor resistances, taking into account temperature correction. The use of three such sensors, mounted on three rods, oriented downward along the axes of a rectangular coordinate system, provides the possibility of measuring the local density with an arbitrary orientation of the probe relative to the vertical. The analysis shows the possibility of measuring the local density of seawater by the hydrostatic method with the required accuracy in probe instruments.

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Muhida, Riza, Muhammad Riza, Hendri Dunan, Bambang Pratowo, Ahmad Cucus, Soewito, Agus Geter Edy Sutjipto, and Rifki Muhida. "Morphology and Conductivity Characteristics of Polycrystalline Silicon Thin Film Deposited by Plasma-Enhanced Vapor Deposition in Textured Substrate." Engineering Innovations 1 (March 25, 2022): 1–6. http://dx.doi.org/10.4028/p-4fjf66.

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We investigate the characteristics of polycrystalline Silicon (poly-Si) thin films for solar cells produced by very high frequency (VHF) plasma enhanced chemical vapor deposition using a conductive scanning probe microscope (SPM). We measure the surface morphology and local current images are simultaneously of the poly-Si layers with a thickness, d=2 mm, formed on textured Ag/SnO2/glass in the range of RMS based-textured substrate (a) s=85nm, (b) s=42nm and (c) s=2nm respectively. Influences of the substrate texture on the crystal growth as well as the local current flow are discussed. Where we found that the average of local current proportional with crystallinity, where the poly-Si layer that has rich crystallinity indicated low conductivity that yield high local current.

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Pereira, Maria J., Joao S. Amaral, Nuno J. O. Silva, and Vitor S. Amaral. "Nano-Localized Thermal Analysis and Mapping of Surface and Sub-Surface Thermal Properties Using Scanning Thermal Microscopy (SThM)." Microscopy and Microanalysis 22, no. 6 (November 21, 2016): 1270–80. http://dx.doi.org/10.1017/s1431927616011867.

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AbstractDetermining and acting on thermo-physical properties at the nanoscale is essential for understanding/managing heat distribution in micro/nanostructured materials and miniaturized devices. Adequate thermal nano-characterization techniques are required to address thermal issues compromising device performance. Scanning thermal microscopy (SThM) is a probing and acting technique based on atomic force microscopy using a nano-probe designed to act as a thermometer and resistive heater, achieving high spatial resolution. Enabling direct observation and mapping of thermal properties such as thermal conductivity, SThM is becoming a powerful tool with a critical role in several fields, from material science to device thermal management. We present an overview of the different thermal probes, followed by the contribution of SThM in three currently significant research topics. First, in thermal conductivity contrast studies of graphene monolayers deposited on different substrates, SThM proves itself a reliable technique to clarify the intriguing thermal properties of graphene, which is considered an important contributor to improve the performance of downscaled devices and materials. Second, SThM’s ability to perform sub-surface imaging is highlighted by thermal conductivity contrast analysis of polymeric composites. Finally, an approach to induce and study local structural transitions in ferromagnetic shape memory alloy Ni–Mn–Ga thin films using localized nano-thermal analysis is presented.

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Kong, Weihang, Lei Li, Lingfu Kong, and Xingbin Liu. "Calibration of Mineralization Degree for Dynamic Pure-water Measurement in Horizontal Oil-water Two-phase Flow." Measurement Science Review 16, no. 4 (August 1, 2016): 218–27. http://dx.doi.org/10.1515/msr-2016-0027.

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Abstract In order to solve the problem of dynamic pure-water electrical conductivity measurement in the process of calculating water content of oil-water two-phase flow of production profile logging in horizontal wells, a six-group local-conductance probe (SGLCP) is proposed to measure dynamic pure-water electrical conductivity in horizontal oil-water two-phase flow. The structures of conductance sensors which include the SGLCP and ring-shaped conductance probe (RSCP) are analyzed by using the finite-element method (FEM). In the process of simulation, the electric field distribution generated by the SGLCP and RSCP are investigated, and the responses of the measuring electrodes are calculated under the different values of the water resistivity. The static experiments of the SGLCP and RSCP under different mineralization degrees in horizontal oil-water two-phase flow are carried out. Results of simulation and experiments demonstrate a nice linearity between the SGLCP and RSCP under different mineralization degrees. The SGLCP has also a good adaptability to stratified flow, stratified flow with mixing at the interface and dispersion of oil in water and water flow. The validity and feasibility of pure-water electrical conductivity measurement with the designed SGLCP under different mineralization degrees are verified by experimental results.

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Алексеев, П. А., Б. Р. Бородин, М. С. Дунаевский, А. Н. Смирнов, В. Ю. Давыдов, С. П. Лебедев, and А. А. Лебедев. "Локальное анодное окисление слоев графена на SiC." Письма в журнал технической физики 44, no. 9 (2018): 34. http://dx.doi.org/10.21883/pjtf.2018.09.46063.17211.

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AbstractA method of local anodic oxidation has been used to obtain graphene-oxide regions on SiC. The change of the surface properties was confirmed by atomic-force microscopy and Raman spectroscopy. Experimental data were obtained on the conductivity, potential, and topography of the oxidized regions. It was shown that the oxidation leads to a rise in the surface potential. A relationship was found between oxidation parameters, such as the scanning velocity and the probe voltage. The method of local anodic oxidation was used to obtain by lithography an ~20-nm-wide nanoribbon and an ~10-nm-wide nanoconstriction.

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37

Mannucci, A. J., B. T. Tsurutani, O. Verkhoglyadova, A. Komjathy, and X. Pi. "Use of radio occultation to probe the high-latitude ionosphere." Atmospheric Measurement Techniques 8, no. 7 (July 16, 2015): 2789–800. http://dx.doi.org/10.5194/amt-8-2789-2015.

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Abstract. We have explored the use of COSMIC data to provide valuable scientific information on the ionospheric impacts of energetic particle precipitation during geomagnetic storms. Ionospheric electron density in the E region, and hence ionospheric conductivity, is significantly altered by precipitating particles from the magnetosphere. This has global impacts on the thermosphere–ionosphere because of the important role of conductivity on high-latitude Joule heating. Two high-speed stream (HSS) and two coronal mass ejection (CME) storms are examined with the COSMIC data. We find clear correlation between geomagnetic activity and electron density retrievals from COSMIC. At nighttime local times, the number of profiles with maximum electron densities in the E layer (below 200 km altitude) is well correlated with geomagnetic activity. We interpret this to mean that electron density increases due to precipitation are captured by the COSMIC profiles. These "E-layer-dominant ionosphere" (ELDI) profiles have geomagnetic latitudes that are consistent with climatological models of the auroral location. For the two HSS storms that occurred in May of 2011 and 2012, a strong hemispheric asymmetry is observed, with nearly all the ELDI profiles found in the Southern, less sunlit, Hemisphere. Stronger aurora and precipitation have been observed before in winter hemispheres, but the degree of asymmetry deserves further study. For the two CME storms, occurring in July and November of 2012, large increases in the number of ELDI profiles are found starting in the storm's main phase but continuing for several days into the recovery phase. Analysis of the COSMIC profiles was extended to all local times for the July 2012 CME storm by relaxing the ELDI criterion and instead visually inspecting all profiles above 50° magnetic latitude for signatures of precipitation in the E region. For 9 days during the July 2012 period, we find a signature of precipitation occurs nearly uniformly in local time, although the magnitude of electron density increase may vary with local time. The latitudinal extent of the precipitation layers is generally consistent with auroral climatology. However, after the storm main phase on 14 July 2012 the precipitation tended to be somewhat more equatorward than the climatology (by about 5–10° latitude) and equatorward of the auroral boundary data acquired from the SSUSI sensor onboard the F18 DMSP satellite. We conclude that, if analyzed appropriately, high-latitude COSMIC profiles have the potential to contribute to our understanding of MI coupling processes and extend and improve existing models of the auroral region.

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V. M. Kornilov, A. N. Lachinov, and A. R. Yusupov. "Visualization of conducting channels in polymer layers by atomic force microscopy with a conducting probe." Technical Physics 92, no. 13 (2022): 2119. http://dx.doi.org/10.21883/tp.2022.13.52232.85-21.

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The results of an experimental study of the local electrophysical properties of ultrathin polymer films by atomic force microscopy with a conducting probe are presented. It is established that visualization of current flow sites (conducting channels) is possible in areas from which the surface layer has been mechanically removed. The conducting channels in the current image have the form of individual points with a height corresponding to the locally flowing current. It is found that the location of the observed channels correlates well with the model of conductivity along the grain boundaries of the supramolecular structure of the polymer. Keywords: thin polymer films, atomic force microscopy with a conducting probe, conducting channels, supramolecular structure.

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WU, Lei. "Methodology for Measurement of Submicron Metallic Wire's Local Electrical Conductivity by Applying Four-points AFM Probe Technique." Journal of Mechanical Engineering 47, no. 04 (2011): 1. http://dx.doi.org/10.3901/jme.2011.04.001.

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40

JU, Bingfeng. "Prototype Atomic Force Microscope System with Micro-four-point Probe for Quantitative Characterization of Local Electrical Conductivity." Journal of Mechanical Engineering 45, no. 04 (2009): 187. http://dx.doi.org/10.3901/jme.2009.04.187.

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41

Malikov, Vladimir N., and Alexey V. Ishkov. "Microstructure and Eddy-Current Analysis of Aluminum 01570 Welded Joints Obtained by Friction Stir Welding." Key Engineering Materials 909 (February 4, 2022): 60–69. http://dx.doi.org/10.4028/p-n129y8.

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The article presents the results of studies of aluminum alloys connected by a welded joint obtained by friction stir welding. During this kind of welding a recrystallized fine-grained microstructure is formed in the joint. The pictures of the weld area microstructure are presented, and the eddy current probe signal variations when scanning the joint are shown. The resulting parameter of the eddy current probe was the local electrical conductivity of the weld area. It is demonstrated that the average grain size of the welded joint microstructure varies in the area of weld defects, which was determined by the signal variation of the eddy current probe. The microstructure peculiarities formed in the weld area where the defects are located, and their influence on the mechanical properties of welded joints are discussed. The results of a series of experiments allow concluding about the qualitative characteristics of the obtained welded joints.

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42

Prasser, H. M., A. Böttger, J. Zschau, and T. Gocht. "Needle shaped conductivity probes with integrated micro-thermocouple and their application in rapid condensation experiments with non-condensable gases." Kerntechnik 68, no. 3 (June 1, 2003): 114–20. http://dx.doi.org/10.1515/kern-2003-0052.

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Abstract The present paper deals with advanced conductivity probes for local void measurements, which were equipped with a microthermocouple, which is integrated into the probe at the place of the electrode wire. These probes were used for rapid transient condensation tests in a heat exchanger pipe immersed into a cooling water tank. The experiments serve as data sources for the validation of thermal-hydraulic system codes concerning the modelling of the condensation, particularly with respect to the behaviour and effect of non-condensable gases. The present tests were carried out at the pressurizer test facility DHVA of the University for Applied Sciences in Zittau/Görlitz, IPM serving as steam source. The slightly downwards inclined condensation tube was connected to the head of the pressure vessel and supplied with steam in this way. The application of a new type of two-phase instrumentation has revealed details about the transient condensation process. Since tests were performed with and without the presence of a non-condensable gas (air), the effect of the gas could be studied. The merits of the probes lie in the ability to distinguish between steam and gas. Without the synchronous temperature and void measurement performed by the probes it would have not been possible to clarify the physical background of the temperature jumps found during the experiments with the non-condensable gas.

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43

Wagner, Tino, Fabian Menges, Heike Riel, Bernd Gotsmann, and Andreas Stemmer. "Combined scanning probe electronic and thermal characterization of an indium arsenide nanowire." Beilstein Journal of Nanotechnology 9 (January 11, 2018): 129–36. http://dx.doi.org/10.3762/bjnano.9.15.

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As electronic devices are downsized, physical processes at the interface to electrodes may dominate and limit device performance. A crucial step towards device optimization is being able to separate such contact effects from intrinsic device properties. Likewise, an increased local temperature due to Joule heating at contacts and the formation of hot spots may put limits on device integration. Therefore, being able to observe profiles of both electronic and thermal device properties at the nanoscale is important. Here, we show measurements by scanning thermal and Kelvin probe force microscopy of the same 60 nm diameter indium arsenide nanowire in operation. The observed temperature along the wire is substantially elevated near the contacts and deviates from the bell-shaped temperature profile one would expect from homogeneous heating. Voltage profiles acquired by Kelvin probe force microscopy not only allow us to determine the electrical nanowire conductivity, but also to identify and quantify sizable and non-linear contact resistances at the buried nanowire–electrode interfaces. Complementing these data with thermal measurements, we obtain a device model further permitting separate extraction of the local thermal nanowire and interface conductivities.

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44

Leitgeb, Verena, Katrin Fladischer, Frank Hitzel, Florentyna Sosada-Ludwikowska, Johanna Krainer, Robert Wimmer-Teubenbacher, and Anton Köck. "SPM—SEM Investigations of Semiconductor Nanowires for Integrated Metal Oxide Gas Sensors." Proceedings 2, no. 13 (December 4, 2018): 701. http://dx.doi.org/10.3390/proceedings2130701.

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Integration of metal oxide nanowires in metal oxide gas sensors enables a new generation of gas sensor devices, with increased sensitivity and selectivity. For reproducible and stable performance of next generation sensors, the electric properties of integrated nanowires have to be well understood, since the detection principle of metal oxide gas sensors is based on the change in electrical conductivity during gas exposure. We study two different types of nanowires that show promising properties for gas sensor applications with a Scanning Probe Microscope—Scanning Electron Microscope combination. Electron Beam Induced Current and Kelvin Probe Force Microscopy measurements with a lateral resolution in the nanometer regime are performed. Our work offers new insights into the dependence of the nanowire work function on its composition and size, and into the local interaction between electron beam and semiconductor nanowires.

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45

Wang, Dewei, Kyle Song, Yucheng Fu, and Yang Liu. "Integration of conductivity probe with optical and x-ray imaging systems for local air–water two-phase flow measurement." Measurement Science and Technology 29, no. 10 (August 23, 2018): 105301. http://dx.doi.org/10.1088/1361-6501/aad640.

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46

Roland, C. M. "ELECTRICAL AND DIELECTRIC PROPERTIES OF RUBBER." Rubber Chemistry and Technology 89, no. 1 (March 1, 2016): 32–53. http://dx.doi.org/10.5254/rct.15.84827.

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ABSTRACT This review describes electrical and dielectric measurements of rubbery polymers. The interest in the electrical properties is primarily due to the strong effect of conductive fillers, the obvious example being carbon black. Conductivity measurements can be used to probe dispersion and the connectivity of filler particles, both of which exert a significant influence on the mechanical behavior. Dielectric relaxation spectra are used to study the dynamics, including the local segmental dynamics and secondary relaxations, and for certain polymers the global chain modes. A recent development in the application of nonlinear dielectric spectroscopy is briefly discussed.

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47

Корнилов, В. М., А. Н. Лачинов, and А. Р. Юсупов. "Визуализация проводящих каналов в полимерных слоях методом атомно-силовой микроскопии с проводящим зондом." Журнал технической физики 91, no. 10 (2021): 1560. http://dx.doi.org/10.21883/jtf.2021.10.51371.85-21.

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The results of an experimental study of the local electrophysical properties of ultrathin polymer films by atomic force microscopy with a conducting probe are presented. It is established that visualization of current flow sites (conducting channels) is possible in areas from which the surface layer has been mechanically removed. The conducting channels in the current image have the form of individual points with a height corresponding to the locally flowing current. It is found that the location of the observed channels correlates well with the model of conductivity along the grain boundaries of the supramolecular structure of the polymer.

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48

Adu, Kofi W., Martin D. Williams, Molly Reber, Ruwantha Jayasingha, Humberto R. Gutierrez, and Gamini U. Sumanasekera. "Probing Phonons in Nonpolar Semiconducting Nanowires with Raman Spectroscopy." Journal of Nanotechnology 2012 (2012): 1–18. http://dx.doi.org/10.1155/2012/264198.

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We present recent developments in Raman probe of confined optical and acoustic phonons in nonpolar semiconducting nanowires, with emphasis on Si and Ge. First, a review of the theoretical spatial correlation phenomenological model widely used to explain the downshift and asymmetric broadening to lower energies observed in the Raman profile is given. Second, we discuss the influence of local inhomogeneous laser heating and its interplay with phonon confinement on Si and Ge Raman line shape. Finally, acoustic phonon confinement, its effect on thermal conductivity, and factors that lead to phonon damping are discussed in light of their broad implications on nanodevice fabrication.

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49

Wernick, Helmut, Patrick Hoelzl, and Bernhard G. Zagar. "Visualization of spatial conductivity irregularities within conductive rubber sheets." COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering 35, no. 4 (July 4, 2016): 1393–402. http://dx.doi.org/10.1108/compel-08-2015-0305.

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Purpose – The purpose of this paper is to present a fast and contactless measurement method to determine the spatial conductivity distribution within an intrinsically conducting polymer, more precisely a conductive rubber sheet specimen. As a consequence of the manufacturing process and the material composition, the conductivity distribution within the sheet is assumed to be inhomogeneous. Design/methodology/approach – The current density distribution within the conductive rubber sheet due to an excitation current is estimated from the measured magnetic field distribution. Therefore, a GMR sensor is used to spatially sample the magnetic field above the specimen. Based on the estimated current density distribution and alternatively the local power dissipation calculated from a thermal image, the conductivity distribution within the specimen is determined. For comparison a reference measurement with a classical resistivity probe is done. Findings – The measurement results show a good agreement between the developed and the classical method. Moreover, the developed measurement method requires less time and still offers a higher spatial resolution. Originality/value – The presented results demonstrate the potential of the developed measurement method for determining the conductivity distribution within thin and planar specimens. Furthermore, conclusions can be drawn about the material homogeneity of the used test specimen.

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50

Agarkova, E. A., M. A. Borik, V. T. Bublik, T. V. Volkova, A. V. Kulebyakin, I. E. Kuritsyna, N. A. Larina, et al. "Influence of phase composition and local crystal structure on the transport properties of ZrO2−Y2O3 and ZrO2−Gd2O3 solid solutions." Izvestiya Vysshikh Uchebnykh Zavedenii. Materialy Elektronnoi Tekhniki = Materials of Electronics Engineering 21, no. 3 (October 31, 2019): 156–65. http://dx.doi.org/10.17073/1609-3577-2018-3-156-165.

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Abstract. The results of investigation of crystal structure, ion conductivity and local structure of solid solutions (ZrO2)1−x(Gd2O3)x and (ZrO2)1−x(Y2O3)x (x = 0.04, 0.08, 0.10, 0.12, 0.14). The crystals were grown by directional crystallization of the melt in a cold container. The phase composition of the crystals was studied by X−ray diffractometry and transmission electron microscopy. Transport characteristics were studied by impedance spectroscopy in the temperature range 400—900 °C. The local crystal structure was studied by optical spectroscopy. Eu3+ ions were used as a spectroscopic probe. The results of the study of the local structure of solid solutions of ZrO2—Y2O3 and ZrO2—Gd2O3 systems revealed the peculiarities of the formation of optical centers, which reflect the nature of the localization of oxygen vacancies in the crystal lattice depending on the stabilizing oxide concentration. It is established that the local crystal environment of Eu3+ Ions in solid solutions (ZrO2)1−x(Y2O3)x and (ZrO2)1−x(Gd2O3)x is determined by the stabilizing oxide concentration and practically does not depend on the type of stabilizing oxide (Y2O3 or Gd2O3). The maximum conductivity at 900 °C was observed in crystals containing 10 mol.% Gd2O3 and 8 mol.% Y2O3. These compositions correspond to the t′′−phase and are close to the boundary between the regions of the cubic and tetragonal phases. It was found that in the system ZrO2—Y2O3 stabilization of the highly symmetric phase occurs at a lower stabilizing oxide concentration than in the system ZrO2—Gd2O3. Analysis of the data obtained allows us to conclude that in this range of compositions the main influence on the concentration dependence of the ion conductivity has a phase composition, rather than the nature of the localization of oxygen vacancies in the crystal lattice.

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Journal articles on the topic 'Local Conductivity Probe'

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