Lateral Inhomogeneities Research Articles

Temperature dependence of interface-state density distributions in Cu/CuO/n-type Si structures

The interface state densities of Cu/CuO/n-Si Schottky structure were investigated by current–voltage (I-V) and capacitance–voltage (C-V) measurements using Roderick and Card’s methods in the temperature range 50–310 K. The interface state density (NSS) as a function of energy distribution (EC-ESS) was extracted from the forward-bias I-V measurements by taking into account the bias dependence of the effective barrier height and series resistance. Furthermore, the values of NSS obtained as a function of temperature. The experimental results have shown that the interface state densities (NSS) value of Cu/CuO/n-Si Schottky structure decreases with increasing EC-ESS values as a function of temperature. Such behavior of interface state densities (NSS) has been explained with variation of the ideality factor as a function of temperature due to lateral inhomogeneities of the barrier height at the metal–semiconductor interface.

Temperature-Dependent Decrease in Efficiency in Power Blue InGaN/GaN LEDs

Temperature-dependent decline in the external quantum efficiency (EQE) of blue light-emitting diodes, which is at a maximum at j 40 A/cm2 the decline in the external quantum efficiency in the continuous-wave and pulsed modes is determined by the loss in nonequilibrium filling by delocalized carriers of states associated with the lateral inhomogeneities in the composition of the solid solution outside the space-charge region, as well as by the loss due to the interaction of delocalized carriers with extended defects.

Electrical properties of inhomogeneous tungsten carbide Schottky barrier on 4H-SiC

In this paper, the electrical behavior of tungsten carbide (WC) Schottky barrier on 4H-SiC was investigated. First, a statistical current-voltage (I–V) analysis in forward bias, performed on a set of equivalent diodes, showed a symmetric Gaussian-like distribution of the barrier heights after annealing at 700 °C, where a low Schottky barrier height (ΦB = 1.05 eV) and an ideality factor n = 1.06 were measured. The low value of the barrier height makes such a WC contact an interesting candidate to reduce the conduction losses in 4H-SiC Schottky diodes. A deeper characterization has been carried out, by monitoring the temperature dependence of the I–V characteristics and the behavior of the relevant parameters ΦB and n. The increase of the barrier height and decrease of the ideality factor with increasing temperature indicated a lateral inhomogeneity of the WC/4H-SiC Schottky contact, which was described by invoking Tung’s model. Interestingly, the temperature dependence of the leakage current under reverse bias could be described by considering in the thermionic field emission model the temperature dependent barrier height related to the inhomogeneity. These results can be useful to predict the behavior of WC/4H-SiC Schottky diodes under operative conditions.

Computationally efficient model of OCT scan formation by focused beams and its usage to demonstrate a novel principle of OCT-angiography

In this paper, we present a computationally highly efficient full-wave model of optical coherence tomography (OCT)-scan formation by focused beams in spectral-domain OCT. Similarly to some previous models, it is based on the summation of fields scattered by discrete sub-resolution scatterers, and enables one to account for the axial and lateral inhomogeneity of the illuminating Gaussian beam. The main feature ensuring the high computational efficiency of the described model is that, rather than numerical integration of the scattered signal over the receiving aperture, we apply an analytical description of both the illuminating-beam focusing and the collection of the scattered signals over the receiving aperture. Elimination of numerical integration over the receiving aperture increases the overall computation speed by a factor of ∼. This is of key importance in terms of the practical feasibility of simulations of 3D OCT data volumes for large amounts (∼) of scatterers, corresponding to realistic densities of cells in biological tissues. We demonstrate the model’s possibilities by simulating the digital refocusing of strongly focused OCT beams in the presence moving scatterers, thereby presenting a novel principle of contrast-agent-free visualization of scatterer flows, with velocities typical of blood microcirculation.

Performance of in situ gamma-ray spectrometry in the assessment of radioactive cesium deposition around the Fukushima Daiichi nuclear power plant

In situ gamma-ray spectrometry using diverse survey platforms has been conducted in contaminated areas with various dose rate levels around the Fukushima Daiichi nuclear power plant (FDNPP). Six survey sites, including two evacuation zones around the FDNPP, were selected for ground-based gamma-ray spectrometry using HPGe (high purity Ge) and LaBr3(Ce) detectors to assess the radioactive cesium deposition in the ground. Laboratory analysis of soil samples taken by depth from the sites was performed to evaluate the depth profile of radioactive cesium. The diverse levels of radioactivity of 137Cs were then distributed to six survey sites from 30 to 3000 kBq·m−2 in the measurement period of October 2018. Finally, a method to directly calculate the depth profile using in situ measurement was introduced so as to have representation over a wide area, and the results were successfully compared with those of sample analysis at one point in the site. Except for the sites with relatively high lateral inhomogeneity of radioactive cesium, about 30% difference between two depth profiling methods using samples and in situ measurement was shown in the calculated radioactivity of 134Cs and 137Cs in the ground.

Correlating facet orientation, defect-level density and dipole layer formation at the surface of polycrystalline CuInSe2 thin films

Individual grains of chalcopyrite solar cell absorbers can facet in different crystallographic directions at their surfaces. To gain a deeper understanding of the junction formation in these devices, we correlate variations in the surface facet orientation with the defect electronic properties. We use a combined analytical approach based on scanning tunneling spectroscopy (STS), scanning electron microscopy, and electron back scatter diffraction (EBSD), where we perform these experiments on identical surface areas as small as 2 × 2 µm2 with a lateral resolution well below 50 nm. The topography of the absorber surfaces indicates two main morphological features: micro-faceted, long basalt-like columns and their short nano-faceted terminations. Our STS results reveal that the long columns exhibit spectral signatures typical for the presence of pronounced oxidation-induced surface dipoles in conjunction with an increased density of electronic defect levels. In contrast, the nano-faceted terminations of the basalt-like columns are largely passivated in terms of electronic defect levels within the band gap region. Corresponding crystallographic data based on EBSD experiments show that the surface of the basalt-like columns can be assigned to intrinsically polar facet orientations, while the passivated terminations are assigned to non-polar planes. Ab-initio calculations suggest that the polar surfaces are more prone to oxidation and resulting O-induced defects, in comparison to non-polar planes. Our results emphasize the correlation between morphology, surface facet orientations and surface electronic properties. Furthermore, this work aids in gaining a fundamental understanding of oxidation induced lateral inhomogeneities in view of the p-n junction formation in chalcopyrite thin-film solar cells.

Two Dimensional Modeling of Au/n-GaN Schottky Device

The current-voltage characteristics are powerfully affected by the lateral inhomogeneity. We developed two dimensional (2D) simulation model for Au/n-GaN Schottky device. In previous studies, it is assumed that zero barrier height inhomogeneity of the device generally good agreement with the Gaussian distribution. In this study, it is accepted that the zero barrier height inhomogeneity is randomly distributed. The structure of the modeling device has columnar grains and gaps between the grains. Structure is divided microcells and every microcell is thought of as a single diode. Whole microcells are connected in parallel. The surface area of the microcells was assumed to be square and circle. In this study, the effect of zero barrier height inhomogeneity and the surface areas of the microcells on the current-voltage characteristics and interface state density are investigated.

Electrical properties of Ga-doped ZnO nanowires/Si heterojunction diode

Herein, we report the high-temperature electrical characteristics of heterojunction diode fabricated based on n-Ga-doped ZnO nanowires/p-Silicon substrate. Various electronic properties such as rectification ratio, the effective barrier height, the diode ideality factor, etc. of the fabricated heterojunction diode at high temperature were investigated. The electrical characteristics were examined in the high-temperature range of 293 K–433 K in both reverse and forward biased conditions, which exhibited good stability over the entire temperature range. The observed current–voltage (I–V) studies confirmed three different conduction mechanisms for the fabricated heterojunction diodes, i.e., either field emission or tunneling, recombination-tunneling mechanism and the transport mechanism dominated by space-charge-limited current at the different regions. The observed electrical results exhibited fluctuations in the sensitivity of the quality factor of the heterojunction diode and consequently corresponding fluctuations in the resistance. The linear dependence of effective barrier height on quality factor can be attributed to the presence of some lateral inhomogeneities in the barrier height. The analysis of C–V data was conducted to deduce the value of barrier height of Schottky barrier for the fabricated heterojunction diode. Interestingly, the observed results assert the mismatch that occurs between the interface states and resulting capacitance of the fabricated heterojunction diode.

Spin excitations in laser-molecular-beam epitaxy-grown nanosized YIG films: towards low relaxation and desirable magnetization profile

We describe the synthesis of nanosized Y3Fe5O12 (YIG) films grown by laser-molecular-beam epitaxy on Gd3Ga5O12 (GGG) and Nd3Ga5O12 (NdGG) substrates with (111) orientation and present the results of ferromagnetic resonance (FMR) and spin-wave propagation studies in these heterostructures. It is found that the magnetic parameters of YIG films grown on NdGG and GGG substrates are considerably different. FMR spectra of YIG/NdGG structures are characterized by a large number of narrow peaks, while FMR spectra of YIG/GGG structures consist of a small number of peaks or one peak. The effective magnetization of YIG films grown on NdGG substrates is less than that of YIG films grown on GGG and is more sensitive to the growth conditions. A lateral inhomogeneity of YIG/NdGG structures is observed in spin-wave propagation experiments. For YIG/NdGG and YIG/GGG structures, the FMR linewidth ΔH of a single peak sharply increases with temperature decrease from 298 to 67 K. The observed increase of ΔH is explained by typical relaxation processes caused by the presence of Fe2 + ions. From the spin-wave propagation study, it is also found that the relaxation of spin-waves explains only a minor part of the FMR single-peak linewidth in YIG/NdGG structures. On the basis of the obtained results, YIG/GGG/semiconductor- and YIG/NdGG/semiconductor-heterostructures with expected low spin-wave relaxation and desirable effective magnetization profile are proposed.

Acoustic properties of strained SiGe/Si layers in the sub-terahertz frequency range

This work studies the scattering of coherent acoustical phonons within the frequency range of 30−200 GHz in strained SiGe/Si heterostructures with uniform SiGe layers and layers where the initial stage of self-organized islands formation was observed. Coherent phonon pulses reflected by single SiGe layers were detected, and phonon interference in the systems composed of two thin (approximately 10 nm) SiGe layers was observed. Acoustical properties were determined for single SiGe layers, and lateral acoustical inhomogeneity of the layers was estimated in the subterahertz frequency range. The results show that within the range of germanium content of 10%−32% acoustical properties of an approximately 10-nm SiGe layer are insensitive to internal strains governed by lattice mismatch and non-uniformities caused by initial stage of Stranski–Krastanov growth. The sound velocity and wave impedance of SiGe layers can be determined within 5% error, using the corresponding parameters of relaxed SiGe solid solutions with the same germanium content.

Electron Tunneling and X-Ray Photoelectron Spectroscopy Studies of the Superconducting Properties of Nitrogen-Doped Niobium Resonator Cavities

We use scanning tunneling microscopy (STM) and spectroscopy (STS), and x-ray photoelectron spectroscopy (XPS) to investigate the effect of nitrogen doping on the surface electronic and chemical structures of cutouts from superconducting $\mathrm{Nb}$ radio-frequency cavities. The goal of this work is to get insights into the fundamental physics and materials mechanisms behind the striking decrease of the surface resistance with the radio-frequency magnetic field, which has been observed on $N$-doped $\mathrm{Nb}$ cavities. Our XPS measurements reveal significantly more oxidized $\mathrm{Nb}$ $3d$ states and a thinner metallic suboxide layer on the $N$-doped $\mathrm{Nb}$ surfaces, which is also confirmed by tunneling spectroscopy measurements. In turn, tunneling measurements performed on native surfaces as well as on $\mathrm{Ar}$-ion sputtered surfaces allow us to separate the effect of $N$ doping on the surface-oxide layer from that on the density of states in the bulk. Analysis of our tunneling spectra in the framework of a model of a proximity-coupled normal layer at the surface [A. Gurevich and T. Kubo, Phys. Rev. B 96, 184515 (2017)] is consistent with the hypothesis that $N$-doping ameliorates lateral inhomogeneities of superconducting properties on the surface and shrinks the metallic suboxide layer. For the $\mathrm{Ar}$ sputtered surfaces, we also find evidence that $N$ doping changes the contact resistance between the metallic suboxide and the bulk niobium toward an optimum value corresponding to a minimum surface resistance. The totality of our experimental data suggests that the $N$ doping provides an effective tuning of the density of states in such a way that it can result in a decrease of the surface resistance with the radio-frequency field, as predicted by calculations of the nonlinear low-frequency electromagnetic response of dirty superconductors. Furthermore, STM imaging of vortex cores shows a slightly reduced average superconducting gap and a shorter coherence length in the $N$-doped $\mathrm{Nb}$ samples as compared to typically prepared $\mathrm{Nb}$ samples, indicating a stronger impurity scattering caused by nitrogen doping in a moderately disordered material.

Detecting lateral inhomogeneity using a 3D Rayleigh wave survey based on numerical simulation and on-site experiment

To deal with the narrow field limitation for the 3D lateral inhomogeneity investigation in the geotechnical engineering, or in urban areas, the paper proposes a radial line survey grid in a cylindrical coordinate system for the Rayleigh wave method. Based upon the cylinder wave features of the wave and the Huygens' principle, the wavefield of the Rayleigh wave recorded by the survey grid can be regarded as a complete 3D wavefield record excited only by one virtual source at the origin, if the energy attenuation is discarded, and the effects of the multiple sources with the conventional 3D survey grid in a rectangular coordinate system are removed. The numerical method simulates the 3D wavefield for homogeneous half-space model and lateral inhomogeneity half-space model (represented by a cavity). The wavefronts of the 3D seismic records with the grid for the numerical models are imaged and the 3D dispersion features of the velocity and ellipticity of the Rayleigh wave are analyzed. Following these, an on-site experiment is carried out using the grid for a 3D detection of a sewage well. The results showed that the 3D seismic records in the far-source region acquired by the survey grid, can directly image the wavefront features of the Rayleigh wave and its distortion by the lateral inhomogeneity in a 3D domain. They also show that the anomalies of the 3D velocity and ellipticity dispersion of the local inhomogeneity are similar to that of water waves are scattered by a solid obstacle, which makes it much easier to recognize a cavity compared to that using the complex dispersion anomalies in a 2D profile or the conventional 3D survey grid in a rectangular system. Moreover, the grid can greatly reduce the work-cost of a 3D survey and be adapted well to narrow areas if the excited source is set at the origin of the radial lines.

Пространственное распределение коэффициента анизотропии в верхней мантии Европы

The radial (transversal) anisotropy of the Earth’s upper mantle was found by comparing the velocity sections of transverse waves obtained by inverse of the dispersion curves of Rayleigh and Love waves. Information on variations in anisotropy with depth was obtained from dispersion curves on fairly uniform oceanic paths. In the oceanic mantle the SH wave velocities obtained from the Love wave data are greater than the SV wave velocities determined from Rayleigh waves, so that the anisotropy coefficient is positive and is about 4% under the Moho boundary and decreases to zero at a depth of about 200 km. The information about the anisotropy of the continents is much more scarce and often contradictory due to a strong lateral inhomogeneity of the crust and upper mantle of the continents. In the European region, some authors reveal the zones where VSV>VSH in the upper mantle, whereas some others confirm VSH>VSV to be everywhere. The uncertainty in the observed values of the anisotropy coefficient is explained by the fact that it was always determined from the results of the Rayleigh and Love wave velocity tomography carried out on the basis of different samples of paths. Accordingly, the values of the SH and SV wave velocities turned out to be averaged over different regions, which led to errors in the estimates of the anisotropy coefficient. To reduce these errors, we proposed an alternative method for estimating the spatial distribution of the anisotropy coefficient: to estimate the anisotropy co-efficient in the beginning at each path and then to fulfill the tomographic inversion for this coefficient. Preliminary results on the distribution of the anisotropy coefficient in the upper mantle of Europe were presented according to an earthquake and seismic noise. However, analysis of the anisotropy coefficient values obtained from the earthquake data and seismic noise has shown that those obtained from noise are usually underestimated. Therefore, in the present study, we used only the data obtained from earthquakes. It was shown that the anisotropy coefficient under the continental part of the European region is close to zero but two areas where VSV>VSH are detected – in the central part of EEP and in southern Italy. In both cases, the negative values of the anisotropy coefficient are observed within the interval of ~60–100 km depth.

Elastic deformations mediate interaction of the raft boundary with membrane inclusions leading to their effective lateral sorting

Liquid-ordered lipid domains represent a lateral inhomogeneity in cellular membranes. These domains have elastic and physicochemical properties different from those of the surrounding membrane. In particular, their thickness exceeds that of the disordered membrane. Thus, elastic deformations arise at the domain boundary in order to compensate for the thickness mismatch. In equilibrium, the deformations lead to an incomplete register of monolayer ordered domains: the elastic energy is minimal if domains in opposing monolayers lie on the top of each other, and their boundaries are laterally shifted by about 3 nm. This configuration introduces a region, composed of one ordered and one disordered monolayers, with an intermediate bilayer thickness. Besides, a jump in a local monolayer curvature takes place in this intermediate region, concentrating here most of the elastic stress. This region can participate in a lateral sorting of membrane inclusions by offering them an optimal bilayer thickness and local curvature conditions. In the present study, we consider the sorting of deformable lipid inclusions, undeformable peripheral and deeply incorporated peptide inclusions, and undeformable transmembrane inclusions of different molecular geometry. With rare exceptions, all types of inclusions have an affinity to the ordered domain boundary as compared to the bulk phases. The optimal lateral distribution of inclusions allows relaxing the elastic stress at the boundary of domains.

Lateral Inhomogeneities of Sapphire Plates Determined with the Aid of X-Ray and Probe Methods

X-ray diffractometry, X-ray profilometry, atomic-force microscopy, and sclerometer tests are employed in the study of R-cut plates of sapphire single crystals grown with the aid of the Kyropoulos technique and used as substrates for the silicon-on-sapphire structures. Regions with different degrees of perfection can be found even on a single plate. Mutually consistent results of the four experimental methods based on different physical principles can be used to reveal regions of structural imperfection on the surface of a plate. It is expedient to employ a complex procedure for multipoint monitoring of the parameters of plates to reduce the number of defect samples that serve as substrates in the production of electronic devices.

Hydration, Solvation, and Isomerization of Methylglyoxal at the Air/Water Interface: New Mechanistic Pathways.

Aqueous-phase processing of methylglyoxal (MG) has been suggested to play a key role in the formation of secondary organic aerosols and catalyze particle growth in the atmosphere. However, the details of these processes remain speculative owing to the lack of a complete description of the physicochemical behavior of MG on atmospheric aerosols. Here, the solvation and hydrolysis of MG at the air/liquid water interface is studied via classical and first-principles molecular dynamics simulations combined with free-energy methods. Our results reveal that the polarity of the water solvent catalyzed the trans-to-cis isomerization of MG at the air/liquid water interface relative to the gas phase. Despite the presence of a hydrophobic group, MG often solvates with both the ketone and methyl groups parallel to the water interface. Analysis of the instantaneous water surface reveals that when MG is in the trans state, the methyl group repels interfacial water to maintain the planarity of the molecule, indicating that lateral and temporal inhomogeneities of interfacial environments are important for fully characterizing the solvation of MG. The counterintuitive behavior of the hydrophobic group is ascribed to a tendency to maximize the number of hydrogen bonds between MG and interfacial water while minimizing the torsional free energy. This drives MG hydration, and our simulations indicate that the formation of MG diol is catalyzed at the air/liquid water interface compared to the gas phase and occurs through nucleophilic attack of water on the carbonyl carbon.

Influence of Crystallographic Orientation on Schottky Barrier Formation in Gallium Oxide

Highly rectifying graphite/I²-Ga2O3 Schottky junctions have been prepared by a simple low-cost drop-casting process. The influence of two different crystal orientations on the current transport mechanism in the graphite-based Schottky junctions was investigated by direct-current (DC) and alternating-current (AC) electrical measurements. The nonideal behavior observed for both $$ \left\langle {\bar{2}01} \right\rangle $$ and $$ \left\langle {010} \right\rangle $$ crystallographic orientations can be explained by the lateral inhomogeneity of the junction related to the imperfection of the graphite/semiconductor interface. A lower density of interface states and their shorter time constants are reported for Schottky junctions formed on $$ \left\langle {\bar{2}01} \right\rangle $$ crystallographic plane, as reflected also by the higher effective barrier height and lower ideality factor.

The effectiveness of a pseudo‐inverse extended Born operator to handle lateral heterogeneity for imaging and velocity analysis applications

ABSTRACTWave equation–based migration velocity analysis techniques aim to construct a kinematically accurate velocity model for imaging or as an initial model for full waveform inversion applications. The most popular wave equation–based migration velocity analysis method is differential semblance optimization, where the velocity model is iteratively updated by minimizing the unfocused energy in an extended image volume. However, differential semblance optimization suffers from artefacts, courtesy of the adjoint operator used in imaging, leading to poor convergence. Recent findings show that true amplitude imaging plays a significant role in enhancing the differential semblance optimization's gradient and reducing the artefacts. Here, we focus on a pseudo‐inverse operator to the horizontally extended Born as a true amplitude imaging operator. For laterally inhomogeneous models, the operator required a derivative with respect to a vertical shift. Extending the image vertically to evaluate such a derivative is costly and impractical. The inverse operator can be simplified in laterally homogeneous models. We derive an extension of the approach to apply the full inverse formula and evaluate the derivative efficiently. We simplified the implementation by applying the derivative to the imaging condition and utilize the relationship between the source and receiver wavefields and the vertical shift. Specifically, we verify the effectiveness of the approach using the Marmousi model and show that the term required for the lateral inhomogeneity treatment has a relatively small impact on the results for many cases. We then apply the operator in differential semblance optimization and invert for an accurate macro‐velocity model, which can serve as an initial velocity model for full waveform inversion.

Dissolved iron in the Bermuda region of the subtropical North Atlantic Ocean: Seasonal dynamics, mesoscale variability, and physicochemical speciation

Water-column data from seven cruises in 2007–2008 reveal pronounced temporal and spatial variations in the distribution of dissolved iron (DFe, <0.4 μm) over the upper 1000 m of the Sargasso Sea near Bermuda, in the western subtropical North Atlantic Ocean. In near-surface waters, DFe exhibits a clear seasonal cycle, increasing from ~0.1–0.3 nM in spring to ~0.4–1.0 nM in summer-early fall. The observed seasonal ranges appear to reflect the extent of winter convective mixing and of summer dust deposition, both of which are closely tied to atmospheric circulation processes. Surface DFe concentrations also show significant (~two-fold) submesoscale lateral variations during summer, perhaps as a result of lateral inhomogeneities in wet deposition and wind-driven mixing. The summer vertical profiles reveal pronounced DFe minima and sometimes deeper maxima in the lower euphotic zone, which likely reflect biological uptake and shallow remineralization, and eddy-driven lateral gradients in these processes. Significant variability is also seen in the mesopelagic zone, with a DFe concentration range of ~0.4–0.7 nM at 1000 m depth, which may reflect mesoscale isopycnal displacements and/or lateral advection of iron-rich waters in the lower thermocline. Physicochemical iron speciation measurements indicate that the major fraction of DFe that accumulates in surface waters of the Sargasso Sea during summer is colloidal-sized Fe(III), which appears to be complexed by strong, iron-binding organic ligands. Concentrations of soluble iron (sFe, <0.02 μm) were considerably lower than DFe in the upper euphotic zone during summer, except over the subsurface DFe minima, where sFe accounts for ~50–100% of the DFe pool. Labile Fe(II), on average, accounted for around 20% of DFe, with maximum concentrations of around 0.1 nM in near-surface waters and in the lower thermocline. The seasonal-scale DFe changes that we have documented near Bermuda are of the same magnitude as basin-scale lateral gradients across the North Atlantic, underscoring the importance of time-series observations in understanding the behavior of trace elements in the upper ocean.

Features of the Electric Response of Rocks to Vibration under Weak Nonuniform Fluid Saturation Conditions

Abstract—The specific features of the electrical response of rocks to vibration in the 0.7–10 kHz frequency range were studied for Berea sandstone cores weakly and inhomogeneously saturated with polar and nonpolar fluids. Fluid was added to the samples with a pipette through a puncture in a protective film. In this case, a strong lateral saturation inhomogeneity was created at the lateral edge of the cylindrical core. During saturation, kerosene (as the nonpolar fluid) and saline aqueous solutions (as the polar fluid) were used in a volume of ~6% of the pore space. The physical modeling results showed that the electric response contains intense second harmonics, the amplitude of which at low frequencies is comparable to the amplitude of the first harmonics. When a 0.5% NaCl solution was added, a significant change in the electrical response in comparison to the response of the core in the initial state was observed only in the 5.45–7.15 kHz frequency range. When kerosene and a 0.05% saline solution was added to the core, an equally strong increase in the electrical response was observed at all frequencies; however, the nature of the spectral change and its temporal dynamics for polar and nonpolar fluids significantly differ. The presented physical modeling results will be useful for understanding seismoelectric processes in a heterogeneous, structurally inhomogeneous natural massif, and may also be the basis for new remote technologies to determine the type of rock saturation.