Resistance-temperature Curves Research Articles

Elastocaloric effect and magnetic properties of rare earth Ce-doped Cu-Al-Mn alloy

In this research, the elastocaloric and magnetic properties of Cu70Al20.5Mn9.5-xCex (x = 0, 0.3, 0.6, 0.9) alloy are systematically studied. The resistance-temperature curve (R-T) revealed that the phase transition temperature range of the alloy is below room temperature (about 230–272 K) and increases as the Ce content increases. In addition, the thermomagnetic curve (M-T) and isothermal magnetization curve (M − H) suggested that the alloy exhibits weak magnetism. The X-ray diffraction pattern shows that the alloy is a single β phase at room temperature. The stress-strain curve shows that with the increase of Ce content, the overall strain of the alloy tends to decrease, indicating that the addition of Ce will increase the compressive modulus of the alloy. The test of elastocaloric properties shows that the maximum adiabatic temperature change of the alloy initially decreases and then increases as the Ce content rises. When the Ce content is 0.3, it exhibits an adiabatic temperature change of 7.4 K under the stress unloading of 500 MPa. The temperature-time cycle test shows that Cu70Al20.5Mn9.2Ce0.3 has good elastocaloric cycle stability.

Forecast of electric transport property via two models

Temperature and synthesis condition-dependent resistivity are critical parameters for determining the electrical properties of materials. Modeling serves as a powerful tool for predicting the electrical transport characteristics of materials. The first objective of this work was to conduct a quantitative analysis of the reported metallic and insulating resistivity behaviors in double-phase materials. Using non-linear regression, both a phenomenological model and an Asym2sig asymmetric peak model were employed to quantitatively analyze the temperature-dependent resistivity. The fitting results align closely with the observed resistivity-temperature curves. The second objective of this work was to establish a method linking chemical composition (synthesis conditions) to the parameters derived from the two models, calculation on the principle of non-linear curve fitting, two numerical equations are highlighted for quantitatively analyzing chemical composition-dependent parameters. The observed effects of chemical composition on the shift in the temperature-resistive curve, which are fundamental to understanding resistivity behavior, are discussed quantitatively for the first time to our knowledge for resistive-temperature behavior. Hence, the resistivity of both crystalline and non-crystalline materials can be forecasted across various compositions and temperatures using the methods presented, even without experimental data.

Effect of Zr4+ on the microstructure and electrical properties of 0.6Y2O3-0.4YCr0.5Mn0.5O3 NTC ceramics

In this study, 0.6Y2O3-0.4YCr0.5Mn0.5O3 negative temperature coefficient (NTC) ceramics doped with different ZrO2 contents were prepared using a two-step sintering method. The effects of Zr4+ content on the microstructure and electrical properties of 0.6Y2O3-0.4YCr0.5Mn0.5O3 were mainly investigated. For the microstructure, X-ray diffraction (XRD) reveals the presence of two main crystalline phases in the samples: Y2O3 and YCr0.5Mn0.5O3. Scanning electron microscopy (SEM) reveals a clear two-phase appearance, and the porosity tends to decrease with the addition of ZrO2. Combined with energy dispersive spectrometer (EDS) to derive the distribution of the elements, Zr4+ is mainly present in the Y2O3 phase, with a small amount in the YCr0.5Mn0.5O3 phase. In addition, the grain sizes of different groups were counted, and the grain size of Y2O3 decreased from 2.73 ± 1.80 μm to 1.65 ± 0.93 μm with the increase of ZrO2 content. For the electrical properties, the resistance-temperature curves were measured from 298.15 K to 1073.15 K, and all the samples exhibited NTC characteristics. And with the increase of ZrO2 content, the resistivity increased from 1.91 × 107 Ω cm to 1.96 × 108 Ω cm, and the B25/100 value decreased from 3315 K to 1310 K. In addition, the chemical state forms of the elements on the surface of the samples were analysed by X-ray photoelectron spectroscopy (XPS), and the valence states as well as the occupancy of the transition elements Cr and Mn were analysed in detail according to the principle of multiple splitting. Finally, the mechanism of influence on microstructure and electrical properties is explained by combining the theory of grain boundary migration and thermal ceramic conductivity.

Preparation of a/c-oriented YBa2Cu3O7−x homogeneous superconducting junctions via pulsed laser deposition

The growth orientation of YBa2Cu3O7−x (YBCO) is extremely sensitive to the growth atmosphere and the heat-treatment temperature. However, according to the existing literature, to obtain YBCO with preferred a-axis orientation, a buffer layer needs to be prepared on the substrate. In this work, YBCO films were grown via pulsed laser deposition, and the influence of N2 and O2 deposition atmospheres on the growth orientation of the YBCO films was studied. It was found that high-quality YBCO films with preferred c-axis orientation can be grown in O2 atmosphere, but it is difficult to grow a-axis-oriented YBCO films in O2 atmosphere without using a buffer layer; however, YBCO films with a high degree of preferred a-axis orientation can be grown in N2 atmosphere without using a buffer layer. Furthermore, an a/c-oriented homogeneous YBCO bilayer with c-axis orientation in the lower layer and a-axis orientation in the upper layer was prepared. X-ray diffraction and scanning transmission electron microscopy results show that the bilayer is epitaxial with a good a/c orientation, and the resistance–temperature curve shows the occurrence of two transitions at temperatures of 91 and 71 K. We believe that these temperatures correspond to the superconducting onset transition temperatures of YBCO in the c- and a-axis growth orientations, respectively. The superconducting current usually flows within the Cu–O plane. With its sudden change in the direction of the current at the interface, the homogeneous junction prepared in this work is expected to provide new ideas for the research of high-temperature superconducting junction devices.

Influence of cationic vacancy diffusion on the aging behavior of low-temperature SrCo1-xRuxO3 thermosensitive ceramics

The thermosensitive ceramics of negative temperature coefficient (NTC), SrCo1-xRuxO3 (0 ≤ x ≤ 0.8), were synthesized using the solid-phase method. The research systematically explored the phase structure, microstructure, elemental chemical states, electrical properties, and aging performance. X-ray diffraction (XRD) data indicates that with the increase of Ru content, the lattice parameter increases. Scanning electron microscopy (SEM) images reveal a dense and uniform microstructure. X-ray photoelectron spectroscopy (XPS) data indicates the presence of Co2+/Co3+ and Ru4+/Ru5+ ion pairs. Resistive temperature data indicates its potential use as a low-temperature thermosensitive resistance material in the range of 2–300 K. Fitting the resistance-temperature curve using the thermally activated band conduction model and Mott's 3D variable range hopping model. Proposed the Ru–O2--Co hopping model, elucidating the hole hopping transport mechanism in NTC ceramics. Impedance spectroscopy analysis indicates that grain boundary resistance dominates the overall resistance of the sample. After aging at 77 K for 864 h, the maximum aging drift rate of the ceramic material is 1.55 %. Proposed a novel cationic vacancy diffusion model to explain aging phenomena, offering a new perspective for designing high-stability low-temperature NTC thermistors.

Electrical and Electro-Thermal Characteristics of (Carbon Black-Graphite)/LLDPE Composites with PTC Effect.

Electrical properties and electro-thermal behavior were studied in composites with carbon black (CB) or hybrid filler (CB and graphite) and a matrix of linear low-density polyethylene (LLDPE). LLDPE, a (co)polymer with low crystallinity but with high structural regularity, was less studied for Positive Temperature Coefficient (PTC) applications, but it would be of interest due to its higher flexibility as compared to HDPE. Structural characterization by scanning electron microscopy (SEM) confirmed a segregated structure resulted from preparation by solid state powder mixing followed by hot molding. Direct current (DC) conductivity measurements resulted in a percolation threshold of around 8% (w) for CB/LLDPE composites. Increased filler concentrations resulted in increased alternating current (AC) conductivity, electrical permittivity and loss factor. Resistivity-temperature curves indicate the dependence of the temperature at which the maximum of resistivity is reached (Tmax(R)) on the filler concentration, as well as a differentiation in the Tmax(R) from the crystalline transition temperatures determined by DSC. These results suggest that crystallinity is not the only determining factor of the PTC mechanism in this case. This behavior is different from similar high-crystallinity composites, and suggests a specific interaction between the conductive filler and the polymeric matrix. A strong dependence of the PTC effect on filler concentration and an optimal concentration range between 14 and 19% were also found. Graphite has a beneficial effect not only on conductivity, but also on PTC behavior. Temperature vs. time experiments, revealed good temperature self-regulation properties and current and voltage limitation, and irrespective of the applied voltage and composite type, the equilibrium superficial temperature did not exceed 80 °C, while the equilibrium current traversing the sample dropped from 22 mA at 35 V to 5 mA at 150 V, proving the limitation capacities of these materials. The concentration effects revealed in this work could open new perspectives for the compositional control of both the self-limiting and interrupting properties for various low-temperature applications.

Electrical transport mechanism of manganite-based trilayer heterostructures in the Cusp and insulating regions

In the present study, efforts are made to study the temperature dependent resistivity (ρ-T) variations of manganites (La0.7Sr0.3MnO3 (LSMO) single layer) and manganites-based systems ((LSMO/γ-Fe2O3/LSMO) trilayer heterostructures) in two distinct regions (Cusp region and Insulating region). Cusp region is an intermediate region between Metallic region and Insulating region. The resistivity-temperature curves are studied and analysed by various resistive models and fitting equations. The co-existence of ferromagnetic clusters and polarons manifests in the Cusp region. The Insulating region is explored and fitted under two regimes: Low Temperature Insulating region and High Temperature Insulating region. Various mathematical models viz. Thermal Activation model, Small Polaron Hopping model and Variable Range Hopping model were employed to study the ρ-T variations under various temperature ranges for LSMO (60 nm) single layer system and LSMO/γ-Fe2O3/LSMO (150 nm) trilayer heterostructures. In Insulating region, the deviations in the fitted curves from the experimental data is due to intrinsic disorder at the R/A site in case of LSMO single layer system while in case of trilayer system disorder exists at both R/A and B sites. The study is crucial to understand the microscopic picture of electrical transport behavior in both the systems near and above Metal-Insulator Transition.

Crystallographic dependence of the electrical transport mechanism in La-Mn-O thermosensitive thin films

Bimetallic oxide materials with amorphous state usually exhibit singular peculiarities due to their periodic disorder structure, implying great potential applications as high-performance electronic devices. In this report, La-Mn-O thin films with different crystallographic features (amorphous and polycrystalline) were deposited on Si (100) substrates using magnetron sputtering method. The as-deposited thin films were successfully convert from the amorphous state to the polycrystalline state by tuning the post-annealing temperatures. X-ray diffraction (XRD) confirmed that La-Mn-O was amorphous at annealing temperatures of 500 °C, while the films were polycrystalline at higher annealing temperatures (600 °C and 700 °C). Scanning electron microscopy (SEM) and high-magnification transmission electron microscopy (HRTEM) distinguished the microscopic features of LaMnO3 thin films in polycrystalline and amorphous states. The effects of annealing temperatures and structural disorder on the temperature-dependent electrical transport properties of La-Mn-O thin films are investigated. The resistance-temperature relationship curves of both polycrystalline and amorphous films show negative temperature coefficient behavior, and the amorphous films follow more than one conduction mechanism. Results show that the electrical transport of the crystalline La-Mn-O films is mainly controlled by thermal activation mechanism, while the electron transport behavior of the amorphous film is simultaneously influenced by thermal activation and Mott VRH variable range hopping conduction.

Widening the temperature range and improving the linearity of CaCu3Ti4O12 ceramics for high-temperature NTC thermistor application through entropy engineering strategy

The entropy engineering strategy has been used for the first time to improve the grain boundary (GB) barrier of CaCu3Ti4O12 (CCTO) ceramics, in order to solve its nonlinear problem at around 300 ℃ and expand its application in the field of high-temperature thermistors. To achieve this goal, we prepared (CaBaEuZnSr)0.2Cu3Ti4O12 (CBEZSCT) high-entropy ceramics, and the GB spontaneous segregation properties were exploited to improve the GB resistance of CBEZSCT ceramics. The results show that the GB activation energy of CBEZSCT high-entropy ceramics (0.87 eV) is higher than that of CCTO ceramics (0.7 eV), which linearizes the resistance temperature curve and extends the application temperature limit from 300° to 750 °C. The proposed method of using a high entropy strategy to tune the GB resistance of CCTO to optimize its performance is highly effective, thus providing a new way of thinking about studying high-performance CCTO materials.

QALIN QATLAMLI TEXNOLOGIYA ASOSIDA TAYYORLANGAN REZISTORLARNING PAST HARORATLARNI SEZMAYDIGAN TENZODATCHIK SIFATIDA QO‘LLANILISHI

A strain gauge made of thick-film resistors has a great potential for use in civil engineering owing to its relatively high voltage sensitivity, stability, low production cost, and long-term service capacities. However, a persistent drawback of strain gauges is their thermal sensitivity. To address this problem, it is advisable to propose and manufacture a strain gauge made of thick film resistors that do not sense low temperatures. This paper makes a close look into the effects of resistor paste components and baking temperature on the temperature coefficient of resistance (TCR) of a thick-film resistor. Thick film resistors made from RuO2 concentrations from 10 wt% to 30 wt% baked at different temperatures on an Al2O3 substrate, have been investigated. The relationship between resistor resistance, TCR and scale factor (GF) has been subject for studies. Findings show that TCR rises with an increase of the RuO2 concentration and baking temperature. Near the minimum (Tmin) of the resistance-temperature curve, the temperature has the least effect on the resistance value, and a thick-film resistor can be considered insensitive to temperature in a certain range. The ratio of TCR to GF and Tmin depends on the film resistance of thick film resistors. By varying the concentration of the conductive phase and the baking temperature, the film resistance of thick-film resistors can be controlled, and low-temperature strain gauges can be achieved for different ambient temperatures.

Structural and electronic properties of Weyl semimetal WTe2 under high pressure

The structural and electronic properties of WTe2 are studied from ambient pressure to 30.0 ​GPa. The pressure-induced structural phase transition is found from Td phase to 1T′ phase above 10.0 ​GPa by lattice offset, which is also reflected at approximately 11.2 ​GPa based on the discontinuous electrical parameters. A pair of hole wave and electron wave packets of Td phase gradually overlap revealing the reversible Td-to-1T′ phase structural transition. WTe2 is observed to undergo semimetal-to-semiconductor transition owing to the calculated energy band up to 15 ​GPa, which is also observed at 11.2 ​GPa according to the resistivity-temperature curves under compression and decompression conditions. The electronic density of states at the Fermi level is mainly contributed by the d orbital of W and the p and s orbital of Te. The photoconductivity property is shown by the theoretical and experimental methods.

Tuning of electrical properties of xBi(Zn0.5Ti0.5)O3-(1-x) (Ba0.5Sr0.5)TiO3 ceramics by composition design and bandgap engineering

Herein, the xBi(Zn0.5Ti0.5)O3-(1-x) (Ba0.5Sr0.5)TiO3 (x = 0.05, 0.10, 0.15, 0.20) novel negative temperature coefficient (NTC) ceramic materials were fabricated by solid-state method. X-ray diffraction revealed that xBi(Zn0·5Ti0.5)O3-(1-x) (Ba0.5Sr0.5)TiO3 successfully formed solid solution. The UV–vis diffuse spectra of the samples indicate that the band gap increases with the increasing Bi(Zn0·5Ti0.5)O3 content. The resistance temperature curve showed that with the increase of Bi(Zn0·5Ti0.5)O3 content, the resistivity ρ of the ceramics at 400 °C increased from 5.96 × 106 to 2.67 × 107 Ω cm, as well as an increase in the B400/800 from 12374.6 to 13469.1 K. The enhanced resistivity is attributed to the increased band gap and reduced carrier pairs caused by the Bi(Zn0.5Ti0.5)O3 modification. The impedance data indicates that the conduction process is activated by thermal. The ceramic samples exhibit the excellent NTC characteristics over a range of 400 °C–1000 °C. Hence, the xBi(Zn0.5Ti0.5)O3-(1-x) (Ba0.5Sr0.5)TiO3 ceramics have the potential to become high temperature NTC ceramics that can operate in a wide temperature range.

Effects of Thallium fluoride substitution on the flux pinning energies of (Cu0.5, Tl0.5)Ba2Ca2Cu3O10-δ superconductors

In the present work, the magnetoresistance behavior of (TlF)x-substituted (Cu0.5,Tl0.5)Ba2Ca2Cu3O10−δ superconducting samples, with x = 0.0, 0.1, 0.2, 0.3 and 0.4, was investigated. According to the thermally activated flux creep (TAFC) model, the flux pinning energies U(H, T) were calculated from the resistivity temperature (ρ–T) curves at applied DC magnetic fields ranging from 0.29 to 4.44 kOe. The results indicated that flux pinning energy was increased with increasing the F-substituting up to x = 0.1 and then decreased with increasing the applied field up to 4.44 kOe. Moreover, significant resistive broadening (ΔT) was observed with increasing the values of the applied magnetic fields. Furthermore, the (TlF)x substitution, boosting the transport critical current density Jc(0) and irreversibility magnetic field Hirr(0) up to x = 0.1 and then decreasing for x > 0.1 at various applied magnetic fields, demonstrates strong flux pinning for x = 0.1.

Effect of Martensitic Transformation of NiTi Particles on Temperature Sensitivity of Flexible VGCF/PDMS Films

AbstractA novel NiTi/vapor grown carbon fiber (VGCF)/polydimethylsiloxane flexible film is successfully prepared, of which the resistivity can keep stable under various strain deformation. By introducing NiTi particles with appropriate phase transition temperature, the resistivity change value of the composite in the temperature range can be doubled without affecting the flexibility of the composite. A computer simulation based on percolation network (PN) theory and Monte Carlo (MC) calculation is developed to understand the mechanisms of resistivity temperature curves. The simulation results agree with experiments quantitatively, which reveal that the inhomogeneous martensitic transformation of NiTi particles is a dominant mechanism for the enlarged and nonlinearity resistivity temperature variation of the composite. Parametric studies have been conducted and the calculation results show that selecting NiTi particles with smaller particle diameter, VGCF with higher conductivity, and polymer with larger coefficient of thermal expansion is conducive to further obtain flexible composite films with better temperature sensitivity.

Infrared Spectroscopy and Excess Conductivity Analysis for (Y3Fe5O12)x/Cu0.5Tl0.5Ba2Ca2Cu3O10-δ Composites

In this study, the influence of adding Yttrium iron garnet (Y3Fe5O12) nanoparticles (NPs) on the microstructure and fluctuation-induced conductivity (FIC) of Cu0.5Tl0.5Ba2Ca2Cu3O10-δ (CuTl-1223) superconductor was studied. Y3Fe5O12 NPs were produced by the co-precipitation technique. By solid state route, (Y3Fe5O12)x/Cu0.5Tl0.5Ba2Ca2Cu3O10-δ composites, with x = 0.00, 0.02, 0.04, 0.06, 0.08, and 0.10 wt. % were prepared. The tetragonal unit cell parameters of (Y3Fe5O12)x/Cu0.5Tl0.5Ba2Ca2Cu3O10-δ composites were found to be invariable with Y3Fe5O12 content. The volume fraction of the host phase was increased with Y3Fe5O12 addition till x = 0.04 wt. %. The different vibrational modes of the samples were identified through Fourier transform infrared spectroscopy (FTIR). The transition from normal to the superconducting state, for the prepared composites, was done through d.c resistivity measurements from room temperature down to zero critical temperature (T0). The Aslamazov–Larkin (AL) model was used to examine fluctuation regions in resistivity-temperature curves. At high temperatures, short wave fluctuation was observed. A cross-over between short wave fluctuation and the mean-field region was spotted at lower temperatures. The mean field region for the examined composites was composed of two-dimensional fluctuations along with one-dimensional fluctuation. The coherence length along the c-axis ζc(0), interlayer coupling (J), and anisotropy parameter (γ) were estimated from the Lawrence–Doniach (LD) model as a function of Y3Fe5O12 content.

Enhanced linearity of CaCu3Ti4O12 by changing energy band structure induced by Fe3+ doping for high temperature thermistor application

Polycrystalline oxide materials exhibit semiconductor properties due to grain boundary (GB) and grain characteristics, which enrich the variety of applications. However, how to regulate the energy band structure of grains and the potential barriers at GBs through defect engineering is crucial to achieve a high performance electronic device. Herein, it is found that Fe3+ ions can change the grain energy band structure of CaCu3Ti4O12 (CCTO) materials, which enhances the linearization of the resistance–temperature curve (lnρ–1000/T) in the high temperature region. First principles calculation indicates that Fe3+ doping narrows the forbidden band and induces new impurity energy levels in the forbidden band, which matches the conclusion that the resistivity–temperature dependence of grains shifts toward the low-temperature region as derived from impedance spectroscopy. This shift results in no monotonic variation in grain resistivity within the application temperature region, thus enhancing the linearity of the lnρ–1000/T curve of CCTO materials in the high temperature region. In addition, Fe3+ ions can modulate the activation energy of CCTO materials in a wide range by changing the activation energy of GBs, which broadens the temperature range of CCTO. The significance of this work lies not only in achieving linearization of CCTO materials for high temperature thermistor application, but more importantly, the method presented here provides an avenue for the study of polycrystalline semiconductor materials.

Variable range hopping conduction mechanisms in reduced rutile TiO2

In this study, obtained samples via reducing Rutile TiO2 by Mg are analyzed to determine the titanium suboxide phases and the dominant structural phase in each sample. By increasing the heat treatment temperature or the amount of reducing agent (Mg), the amount of suboxide phases Ti n O2n−1 (1 ≤ n < 10) with the lower n values increases, and TiO is the main phase in the samples with a low electrical resistivity. The hopping conduction mechanism is also investigated in the temperature range of 11.5–300 K, and the characteristic parameters describing the conduction mechanism are determined and discussed. For samples with a low electrical resistivity, the nearest neighbor hopping (NNH) conduction mechanism governs the charge transport properties below 220 K, and a transition from the NNH to the Mott-variable range hopping (VRH) conduction regimes is observed at ∼65 K. In addition, the Efros-Shklovskii (ES)-VRH conduction process governs at low temperatures below 18 K, and the last crossover from the Mott-VRH to the ES-VRH models illustrates the strong electron-electron Coulomb interaction, which leads to the Coulomb gap (∼1 meV) at low temperatures. According to the obtained hopping parameters, the low resistivity samples are close to the metal-insulator transition. For samples with a high electrical resistivity, the hopping conduction relations are not fitted to the resistivity-temperature curves, and probably it is related to the resistive switching behavior of the material, which changes the nature and conductivity properties, and is depicted in the current-voltage (I-V) curve.

Effect of La-site substitution on the magnetoelectric transport properties of La0.7Ca0.3MnO3 polycrystalline ceramics

A series of La0.64RE0.06Ca0.3MnO3 (RE = Nd, Eu, Gd, Dy, and Er) polycrystalline ceramics were prepared by the sol-gel method. The effects of the substitution element types on the structure, electrical transport properties and magnetic properties of the polycrystalline ceramics were analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM) and other tests. The results show that as the ionic radius of the substitute elements decreases, the cell volume decreases, the grain size increases, the peak resistivity increases exponentially, the metal insulator transition temperature decreases linearly, the temperature coefficient of resistance (TCR) shows a trend of first decreasing and then increasing, the peak TCR of these samples reaches 43.4%, and the magnetoresistance (MR) shows a trend of gradually increasing, reaching 92.4% at a 1 T magnetic field. Based on small polaron hopping（SPH） model, variable range hopping（VRH）model and the phase separation mechanism, fitting the resistivity temperature curves of polycrystalline ceramics shows that elemental doping changes the electrical transport properties mainly by influencing the crystal structure and thus the activation energy Eα. When the radius of the doped element ions is large, the peak TCR is close to dρ/dTmax, so the main influence is the paramagnetic (PM) phase resistance. When the radius of the dopant element ions is small, the peak TCR is far from dρ/dTmax, so the main influence is the ferromagnetic (FM) phase resistance.

Low temperature electrical resistivity on the insulating side of the metal–insulator transition in [formula omitted]semiconductor

In this paper, different hopping theoretical mechanisms have been employed to explain the charge conduction in insulating disordered CdAs2 semiconductor. The low temperature electrical resistivity of four insulating samples, referenced CdAs2(1), CdAs2(2), CdAs2(3) and CdAs2(4) was investigated in order to know the effect of temperature on the carrier transport. A close examination of the resistivity-temperature curves displays that the general hopping process lnρ~T−α is operative at low temperatures in our four samples. The three samples (1), (2) and (3) exhibit crossover behavior between Mott (α = 1/4) and Efros-Shklovskii (α = 1/2) variable range hopping conduction upon variation of temperature, and the crossover criterion is also studied. For sample (4), the experimental results show that the carrier transport obeys T-2/3dependence. A possible explanation of this mechanism has been based on the adaptation of the existing Efros-Shklovskii variable range hopping model. This law is achieved by replacing the conventional Miller-Abrahams expression for hopping probability by another one, which introduces the local energy fluctuations involved in the electron transfer.

High-thermal-stability resistor formed from manganese nitride compound that exhibits the saturation state of the mean free path

Antiperovskite manganese nitride compounds possess the saturation characteristics of the mean free path at an approximate room temperature. Therefore, such compounds show a flat resistance–temperature curve at an approximate room temperature. In this paper, we propose a manganese nitride resistor for high-thermal-stability systems. We fabricated and evaluated the micro/nanoscale manganese nitride compound resistors using the complementary metal-oxide-semiconductor-compatible process. The thermal coefficient of the fabricated manganese nitride compound resistor was as low as that of other near-zero temperature-coefficient of resistivity materials. These results indicate that manganese nitride compounds can achieve higher thermal stability.