Negative Temperature Coefficient Of Resistance Behavior Research Articles

Electrical, Dielectric, and Magnetic Characteristics of (BiBa)(FeMn2)O8

A new compound of chemical formula (BiBa)(FeMn2)O8 is prepared by a solid‐state reaction method. X‐ray structural studies confirm orthorhombic unit cell of the compound. Room‐temperature magnetic data display ferromagnetic hysteresis loop with high value of effective magnetic moments. The dependence of dielectric constant, loss tangent, impedance, and the conductivity at different frequencies (1 kHz−1 MHz) are measured using LCR meter on rise of temperature from room temperature to 500 °C. The dielectric constant increases on rise of temperature due to Maxell–Wagner polarization, and the loss tangent displays similar behavior. A low value of loss tangent is obtained at higher frequencies, which paves the way for the application of the compound in high‐frequency devices. The real impedance of the compound decreases indicating NTCR (negative temperature coefficient of resistance) behavior, and the imaginary impedance displays relaxor behavior. The Nyquist plot fits to a series combination of two RQC circuits ((RQC)(RQC)) and indicates the presence of non‐Debye relaxation. The frequency variation of conductivity obeys Jonscher's power law and reveals different conduction mechanisms in grain and grain boundary regions.

Optical, structural and dielectric properties of solvothermally grown molybdenum sulfide nanosheets

MoS2 nanosheets have been synthesized by simple and conventional solvothermal methods. FEG-TEM images reveal that the produced MoS2 sample has a hexagonal crystal structure with large (2μm) nanosheets. The XRD and Raman spectra of the samples also confirm the hexagonal crystal phase. The schematic refined unit cell with electron density mapping is visualized after Rietveld refinement. The optical properties such as absorbance, PL, refractive index, extinction coefficient, dielectric constant, optical conductivity, etc. have been investigated in the wavelength range of 330nm to 1000nm. The normal dispersion (ND) and the anomalous dispersion (AD) regions have been observed in the refractive index spectrum. The estimated carrier concentration has been found to be 5×104cm−3. The temperature-dependent indirect bandgap of MoS2 has been simulated using a semi-empirical formula based on electron-phonon coupling and it decreases with increasing temperature. The calculated average lifetime of carriers is 1.17 ns. The grown MoS2 shows large dielectric constant and low tangent loss in the frequency range of 5–500 kHz. The Nyquist plot of the sample gives the NTCR (negative temperature coefficient of resistance) behaviour like a semiconductor. The activation energy (EA) has been estimated from temperature dependence AC conductivity.

Enhanced dielectric and magnetic properties of magnetodielectric La2−xPrxCoMnO6 for spintronic applications

La2−xPrxCoMnO6 (x = 0.5, 1.0, 1.5 and 2.0) double perovskites were prepared via sol gel method. X-ray diffraction peak profile inveterate the nonexistence of impurity phases in the prepared system. Rietveld refinement suggested that ordered monoclinic (P21/n) phase exist along with disordered orthorhombic (Pbnm) and rhombohedral (R3c) structural phases. A decrease in unit cell volume and lattice parameters is observed with increase in Pr content which is in agreement with the difference in ionic radii of La and Pr ions. Morphological and compositional study using FESEM with EDX suggested that grain size lies in micrometer range and signifies the purity of developed samples. Dielectric constant as well as tangent loss exhibit dispersive behavior at lower frequencies and higher temperatures. The strong effect of bond angle, anti-site disorder and grain size is observed on dielectric properties. Due to large bond angle and large antisite disorder, LPCMO2 exhibited largest value of dielectric constant among all developed compositions. Cole-Cole plots proposed a non-Debye type relaxation and indicated NTCR (negative temperature coefficient of resistance) behavior for the synthesized compositions. Ac conductivity showed increasing tendency with rise in both frequency as well as temperature. Increase in dc conductivity with temperature proposed semiconducting behavior of prepared samples that can be explained on the basis of Thermal activation (TA) and Variable range hopping (VRH) models. The saturation magnetization (Ms) showed a strong correlation with bond angle, tilting of CoO6/MnO6 octahedra and grain size i.e. LPCMO2 is having largest Ms whereas lowest Ms is exhibited by LPCMO3 which may be due to variation in exchange interaction which strictly depends on bond angle and tilting of MO6 octahedra. Enhanced magnetic properties make these materials useful for spintronic devices and magnetic storage. Dielectric and magnetic properties of the prepared samples depend strongly on ˂Co-O-Mn˃ bond angle and have same variation tendency with Pr substitution which indicates coupling between these properties.

CoMn2O4 and Cu0.5Co0.5Mn2O4 spinels as efficient protective coating layers on SUS430 for SOFC interconnect

In this study, CoMn2O4 and Cu0.5Co0.5Mn2O4 spinels are examined as protective coatings for chromium diffusion in metallic interconnect of solid oxide fuel cell. Both spinels are prepared by co-precipitation technique in order to obtain high temperature conducting spinels. The spinels obtained after 4 h of calcinations in air at 500 °C exhibit tetragonal crystal structure with average grain size between 90 and 100 nm. Cu0.5Co0.5Mn2O4 spinel exhibits superior electrical conductivity over CoMn2O4 and both display NTCR (negative temperature co-efficient of resistance) behavior illustrating their use as a protective layer on interconnects for fuel cells operating at higher temperatures. Doctor-blade employed spinel coating over SUS430 alloy exhibits good adhesion between protective spinel layer and metallic alloy. Cross section micrographs reveal presence of nanosized and highly dense grains capable to resist the outflow of chromium ions present in SUS430. Mass gain and diffusion rate constant (Kp) was high for CoMn2O4 coated SUS430 illustrating Cu0.5Co0.5Mn2O4 spinel as a better protective coating layer for interconnect application. Chromium outflow is restricted and the same is evident from all cross-section micrographs of spinel coated SUS430 specimens subjected for oxidation up to 1000 h. Estimated thickness of Cr2O3 layer was ∼15 nm for CoMn2O4 whereas Cu0.5Co0.5Mn2O4 coated SUS430 specimen had ∼12.5 μm thickness at the SUS430/spinel interface demonstrating superior resistance to chromium outflow. The area specific resistance was lowest for Cu0.5Co0.5Mn2O4 coated specimen (between 14 mΩcm2 – 15 mΩcm2) followed by CoMn2O4 coated specimen reiterating Cu0.5Co0.5Mn2O4 as efficient protective coating material for SUS430 SOFC interconnect.

Development of a novel triple perovskite barium bismuth molybdate material for thermistor-based applications

In this communication, development (synthesis and characterization) of a novel triple perovskite sample Ba3Bi2MoO9 (BBMO) is reported. The material has monoclinic crystal symmetry. A detailed study of microstructure and compositional analysis of the sample by using scanning electron microscopy (SEM) and EDX (energy dispersive X-rays) spectrum has provided the quality of the BBMO ceramic. The topological and surface roughness of the novel material has been analyzed to clarify the surface texture and compactness of the sample surface. The variation of conductivity under the alternating current of the material varies according to the Jonscher's universal power law. The high dielectric constant and low tangent loss are applicable for fabrication of various electrical instruments. The resistance decreases with an increase in temperature supports the NTCR (negative temperature coefficient of resistance) behavior, which is clarified by using TCR and β (thermistor constant) for NTC thermistor application.

Dielectric spectroscopy and ferroelectric studies of multiferroic bismuth ferrite modified barium titanate ceramics for energy storage capacitor applications

This study reports a single-phase solid-solution of barium titanate- bismuth ferrite (1-x) BaTiO3-xBiFeO3 (x = 0.0, 0.1, 0.2 and 0.3, abbreviated as BTO, BTBF1, BTBF2 and BTBF3) composition fabricated via conventional solid-state reaction technique. The BFO modified BTO ceramics exhibit a single perovskite structure with pseudo-cubic (x ≥ 0.1) symmetry, and the c/a ratio decreases with an increase in BFO content. Dielectric studies suggest that the ferroelectric-paraelectric phase transition around 150 °C for BTBF1 ceramic increases to 180 °C for BTBF3 ceramic, attributed to the higher transition temperature of BFO ceramic. The temperature-dependent impedance studies suggest non-Debye type relaxation and NTCR (negative temperature coefficient of resistance) behavior of the composition. Among the prepared ceramics, BTBF1 ceramic showed an improved energy density of 39.91 mJ/cm3 and energy efficiency of 60.92%. Thus, prepared ceramics can be considered a potential candidate for energy storage applications.

Structure, electrochemical impedance and Raman spectroscopy of lithium-niobium-titanium-oxide ceramics for LTCC technology

Resultsof Electrochemical Impedance Spectroscopy (EIS) are reported for lithium-niobium-titanium-oxide (LNTO) ceramics synthesized by a solid-state reaction method with two functional additives (MoO3 or ZnO) in the temperature range 323 K - 573 K and frequencies between 10−1 Hz and 107 Hz. Scanning electron microscopy (SEM) reveals a textured morphology of rod and plate-like particles that are typical for M-phase LNTO materials, while X-ray diffraction (XRD) analysis confirms the formation of an M-phase member compound with an approximate structure of Li7Nb3Ti5O21. Complex impedance analysis indicates that its overall electrical resistivity behavior depends mostly on the grain boundary processes. EIS analysis shows a negative temperature coefficient of resistance behavior (NTCR) in a defined temperature range in two LNTOs and thermal activation of the conduction mechanisms. The low dielectric constants of 5.5 and 12.1 at 1 MHz were found for the first and second LNTOs, respectively. Complimentary Raman spectroscopic measurements, despite very large crystallographic unit cell of LNTO, reveal only a small number of lines, which is the consequence of a “molecular” nature of materials.

Structure, electric and dielectric properties of PbFe1/3Ti1/3W1/3O3 single perovskite compound

A conventional solid-state method was used to prepare Pb(Fe1/3Ti1/3W1/3)O3 single perovskite material. The sample sintered at 900?C was studied by XRD and after Rietveld refinement the orthorhombic structure with Pbam space group was confirmed. The FTIR frequency bands corresponding to Pb-O, Ti-O, O-lattice, W- O-W and Fe-O stretching vibrations together with the XRD data also confirmed that Fe2+ and W6+ ions are incorporated in the structure and most probably substituted Ti4+ ions at the B site of the perovskite ABO3 structure. The average grain size of the perovskite ceramics, estimated from SEM micrograph, was 1 to 2 ?m. Variation of dielectric properties and AC conductivity with frequency and temperature revealed that the material had semiconducting nature and negative temperature coefficient of resistance (NTCR). The Nyquist plots were modelled with an equivalent circuit consisted of parallel capacitance, resistance and constant phase element corresponding to the grains (bulk) and grain boundaries. It was observed that grain resistance (Rb) of the sample decreases with the rise of temperature, which supports the NTCR behaviour. The semi-circular arcs of the Nyquist and Cole-Cole plots confirm the semiconducting nature of the sample.

Structural, dielectric and electrical properties of BaSnO3 and BaSeO3 modified Bi0.5Na0.5TiO3 ceramics

In this communication, preliminary structural and detailed electrical (dielectric, polarization, impedence, and conductivity) characteristics of BaSnO3 and BaSeO3 modified complex Bi0.5Na0.5TiO3 ceramics with a general chemical formula and composition, (1–2x)[(Bi0.5Na0.5) TiO3]+x(BaSnO3)+x(BaSeO3) (with x = 0, 0.05, 0.1, 0.15) (BNT–BSn–BSe) ceramics, synthesized by a high-temperature mixed-oxide technique (calcinations temperature = 925 °C and sintering temperature = 950 °C, for time = 4 h each) have been reported. Analysis of room temperature X-ray diffraction data has confirmed the formation of single phase perovskite of BNT–BSn–BSe in rhombohedral phase and provided crystal data. Studies of impedance spectroscopy and electrical conductivity of the materials in a frequency range of (1 kHz-1MHz) at different temperatures (25–500 °C) have shown the composition (x) effect on electrical characteristics of BSn and BSe modified BNT.The electric field dependent polarization study at room temperature exhibits the existence of ferroelectricity in the materials. Study of the impedance spectroscopy through Nyquist plots shows the contributions of the grains and grain boundary in the resistive and capacitive properties of the materials. This study also determines the existence of NTCR (negative temperature coefficient of resistance) behavior the prepared materials. The J–E characteristics demonstrate the Ohomic behavior with slope closer to 1.

Structural, dielectric and electrical behavior of Bi0.85Tm0.15FeO3 ceramic

The (Bi0.85Tm0.15)FeO3 (BTFO) and BiFeO3 (BFO) ceramic compounds have been prepared by using a standard ceramic technology (i.e., high-temperature solid-state reaction route). The formation of the above compounds was checked by the detailed analysis of X-ray diffraction (XRD) data using standard computer programming software ‘POWD’. All the diffraction peaks of the XRD patterns of the above compounds were indexed through JCPDS files of X'Pert High Score plus. These compounds (BFO and BTFO) were found to crystallize in rhombohedral symmetry with few impurity phases present in the structure. A dielectric peak observed in a temperature range of 250C–350 °C is due to the magnetic phase transition occurring in the materials (BFO and BTFO). The calculated value of tolerance factor reveals the degree of distortion occurring in the ideal perovskite structure. Impedance study indicates the presence of both NTCR (negative temperature coefficient of resistivity) and PTCR (positive temperature coefficient of resistivity) behavior in a different temperature range. The role of grain and grain boundary effects in the electrical properties was discussed with the respective fitting parameters (Rg, Rgb, CPE etc.) of the materials. Activation energy has been calculated at different temperature through Nyquist plot, and also from the slopes of Arrhenius (σac∼1/T) plot. The polarization versus electric field (PE) hysteresis loops of BFO and BTFO gave the evidence of ferroelectric behavior present in the compounds.

Investigation of structural, morphological and NTCR behaviour of Cu-doped ZnO nanoceramics synthesized by high energy ball milling

Abstract Nanocrystalline Cu doped ZnO (Zn1-xCuxO, x = 0, 0.01, 0.02, 0.03 and 0.04) samples were synthesized by high energy ball milling technique (HEBM). The strain developed during ball milling and incorporation of Cu into the Zn-site in ZnO lattice is depicted as broadening of the full width at half maximum (FWHM) of the XRD. The X-ray diffraction peak-widths (FWHM) increases with increase in Cu-concentration. Furthermore, the mechanical impact and the heat produced during ball milling helps in the formation of aggregates. The size of these aggregates was observed to increase with Cu-concentration. Upon calcination, these aggregated structures form particle, resulting in bigger particles for higher concentration of Cu. The XRD results confirm that up to ∼3 at% of Cu can be doped in ZnO lattice, beyond which CuO precipitates. The impedance spectroscopy and the ac-conductivity results confirm the improvement in dielectric properties of ZnO by Cu doping. The decrease in magnitude of Z′ on increase in temperature confirms the negative temperature coefficient of resistance (NTCR) behaviour of the samples. The ac conductivity of ZnO decreases with Cu doping and follows the correlated barrier hopping (CBH) model in the investigated temperature and frequency range.

Study of the structural and electrical behavior of Bi(Mg,Ti)O3 modified (Ba,Ca)TiO3 ceramics

The ability of BaTiO3 to form solid solutions with different dopants (both iso- and aliovalent) makes it versatile for various applications. In the present study, (Ba,Ca)TiO3 (BCT) is modified with Bi(MgTi)O3 (BMT) in search for new lead-free ferroelectric material and improve their properties. For this purpose, BCT acts as a main base material and BMT acts as a modifier to fabricate a multifunctional material. In this study, we report the structural and electrical properties of lead free piezo-ceramics ([Formula: see text])(Ba[Formula: see text]Ca[Formula: see text])TiO3–[Formula: see text]Bi(Mg[Formula: see text]Ti[Formula: see text])O3 with [Formula: see text], 0.4, 0.5 prepared by solid-state sintering technique. Single perovskite phase with tetragonal structure is obtained for all the compositions, which is reconfirmed by the Raman Spectroscopic study. Dielectric study confirm the temperature stable behavior of the dielectric permittivity values above 300[Formula: see text]C. The dielectric constant value decreases with increase in BMT doping content. Impedance Spectroscopic study confirms non-Debye type dielectric relaxation in the specimen. The Nyquist plot and conductivity studies show the negative temperature coefficient of resistance behavior (NTCR) of the samples.

Pyroelectric Response and Conduction Mechanism in Highly Crystallized Ferroelectric Sr3(VO4)2 Ceramic

We present a study on the ferroelectric phase transition, pyroelectric properties, and conduction mechanism of highly crystallized strontium orthovanadate (Sr3V2O8) ceramic, prepared by a solid-state reaction technique. X-ray diffraction studies show the formation of a single-phase compound in trigonal crystal system. Detailed studies of dielectric parameters (er and tan δ) of the compound as a function of temperature and frequency reveal their independence over a wide range of temperature and frequency. An anomaly in er suggests the possible existence of a ferroelectric–paraelectric phase transition of diffuse type in the material, which is confirmed by electric polarization and pyroelectric studies. The low dielectric loss and moderate relative permittivity make this material (with suitable modifications) a potential candidate for use in microwave applications. The low leakage current and negative temperature coefficient of resistance (NTCR) behavior of the sample have been verified from J–E plots. The nature of the variation of the direct-current (DC) conductivity with temperature confirms the Arrhenius and NTCR behavior of the material.

Development of bismuth-based electronic materials from Indian red mud

This paper reports the synthesis and characterization of bismuth-based new electronic materials fabricated from silicon-free Indian red mud (RM). The materials were prepared using a solid-state reaction technique. Preliminary X-ray (XRD) structural analysis exhibits the formation of compounds closely related to BiFeO3 (with the presence of some additional impurity phases). The surface morphology recorded by scanning electron microscopy (SEM) reveals a polycrystalline nature of texture with uniform distribution of grains. Some dielectric parameters (relative permittivity (εr) and tangent loss (tanδ)) of the compounds are almost independent on frequency in the low-temperature range. In the high- temperature region, relative permittivity of the compounds is found to be higher with low tangent loss. Detailed studies of impedance and related parameters exhibit that the parameters are strongly dependent on temperature, and show a good correlation with their microstructures. The bulk resistance, evaluated from complex impedance spectra, is found to be decreasing with rise in temperature. The nature of impedance spectra exhibits a typical negative-temperature-co-efficient of resistance (NTCR) behavior similar to the semiconductors. Studies of electric modulus show the presence of hopping conduction mechanism in the system with non-exponential type of conduction relaxation. The low-leakage current and NTCR behavior of the materials are found to be consistent with their J–E characteristics. The ac conductivity spectra of the materials show a typical-signature of an ionic conducting system, and are found to obey Jonscher׳s universal power law.

Pyroelectric and dielectric properties of lead-free ferroelectric Ba3Nb2O8 ceramic

The present study highlights ferroelectric phase transition, dielectric, pyroelectric properties and conduction mechanism of highly crystallized barium orthoniobate (Ba3Nb2O8) ceramic, prepared by a solid-state reaction technique. X-ray diffraction studies show the formation of a single-phase compound in hexagonal crystal system. Detailed studies of dielectric parameters (εr and tanδ) of the compound as a function of temperature and frequency reveal their independence over a wide range of temperature and frequency. An anomaly in εr suggests the possible existence of a ferroelectric–paraelectric phase transition of diffuse-type in the material. The low dielectric loss and moderate relative permittivity make this material (with certain modification) a potential candidate for microwave applications. Studies of pyroelectric properties reveal that the materials have reasonably high figure of merit useful for fabrication of pyroelectric detectors. The low-leakage current and negative temperature coefficient of resistance (NTCR) behavior of the sample have been verified from J–E plots. The nature of variation of dc conductivity with temperature confirms the Arrhenius and NTCR behavior of the material.

Frequency and temperature dependence behaviour of impedance, modulus and conductivity of BaBi4Ti4O15 aurivillius ceramic

In this work, we report the dielectric, impedance, modulus and conductivity study of BaBi4Ti4O15 ceramic synthesized by solid state reaction. X-ray diffraction (XRD) pattern showed orthorhombic structure with space group A21am confirming it to be an m=4 member of the Aurivillius oxide. The frequency dependence dielectric study shows that the value of dielectric constant is high at lower frequencies and decreases with increase in frequency. Impedance spectroscopy analyses reveal a non-Debye relaxation phenomenon since relaxation frequency moves towards the positive side with increase in temperature. The shift in impedance peaks towards higher frequency side indicates conduction in material and favouring of the long rangemotion of mobile charge carriers. The Nyquist plot from complex impedance spectrum shows only one semicircular arc representing the grain effect in the electrical conduction. The modulus mechanism indicates the non-Debye type of conductivity relaxation in the material, which is supported by impedance data. Relaxation times extracted using imaginary part of complex impedance (Z??) and modulus (M??) were also found to follow Arrhenius law. The frequency dependent AC conductivity at different temperatures indicates that the conduction process is thermally activated. The variation of DC conductivity exhibits a negative temperature coefficient of resistance behaviour.

Development of electronic materials from industrial waste red mud

The current research work presents the preparation and characterization of some new electronic materials using bismuth oxide (Bi2O3) and industrial waste red mud in different proportion by weight using a cost-effective mixed-oxide technique. Preliminary X-ray structural analysis exhibits the formation of compounds with structure analogous to that of BiFeO3 compound along with some impurity phases. Studies of dielectric parameters (er and tanδ) of these compounds as a function of temperature and frequency exhibit that they are almost temperature independent in the low temperature range and possess high relative permittivity with low loss in the high temperature range. Detailed studies of impedance and related parameters exhibit that the electrical properties of these materials are strongly dependent on temperature, and bear a good correlation with their microstructures. The bulk resistance, evaluated from complex impedance spectra, is found to be decreasing with rise in temperature, exhibiting a typical negative temperature co-efficient of resistance (NTCR)—type behavior similar to that of semiconductors. Studies of electric modulus indicate the presence of hopping conduction mechanism in the system with non-exponential type of conductivity relaxation. The low leakage current and NTCR behavior of the sample have been verified from I–V characteristics. The nature of variation of dc conductivity with temperature confirms the Arrhenius and NTCR behavior in the material. The ac conductivity spectra show a typical-signature of an ionic conducting system, and are found to obey Jonscher’s universal power law.

Phase transition and conduction mechanism in Pb2Na0.8R0.2Nb4.8Fe0.2O15 material (R=rare earth)

Electrical properties of Pb2Na0.8Eu0.2Nb4.8Fe0.2O15 tungsten bronze compound were investigated. Ferroelectric phase transition of diffuse type is observed at 395°C. Conductivity study as a function of temperature (RT-600°C) and at three different frequencies (10, 100 and 1000kHz) suggests the existence of dominant ionic conduction. The rise of ac conductivity on increasing temperature supports the NTCR (negative temperature coefficient of resistance) behaviour of the material. The activation energies have been evaluated from ac conductivity using Arrhenius equation and discussed. Different conduction mechanisms were identified. For comparison, the conducting properties of Pb2Na0.8R0.2Nb4.8Fe0.2O15 (R=Dy, Nd, La) were also investigated.

Studies of dielectric, pyroelectric and conduction mechanism of Sr3Ta2O8

Abstract The current research work reports on structural, dielectric, pyroelectric and conduction properties of strontium orthotantalate, prepared by using a high-temperature solid-state reaction technique. Preliminary x-rays structural study of the material confirms the formation of a single-phase compound with trigonal crystal structure. The microstructure of gold-coated pellet sample recorded by scanning electron microscopy (SEM) shows well-defined and homogeneously distributed grains. Detailed studies of dielectric parameters ( e r and tan δ ) of the compound as a function of temperature at some selected frequencies reveal that these parameters are invariant in a wide range of frequency and temperature (room temperature to about 400 °C). Studies of pyroelectric properties reveal that the materials have reasonably high figure of merit useful for fabrication of pyroelectric detector. The ac conductivity spectra show a typical-signature of an ionic conducting system, and are found to obey Jonscher's universal power law. The low leakage current and negative temperature coefficient of resistance (NTCR) behavior of the sample have been verified from J ~ E plots. The nature of variation of dc conductivity with temperature confirms the Arrhenius and NTCR behavior in the material.

Dielectric and Impedance Spectroscopy of Barium Orthoniobate Ceramic

Barium orthoniobate (Ba3Nb2O8), a derivative of the perovskite family, was prepared using a high-temperature solid-state reaction technique (calcination temperature = 1425°C and sintering temperature = 1450°C for 4 h). Preliminary x-ray structural analysis with room-temperature x-ray diffraction data confirmed the formation of a single-phase compound with hexagonal crystal structure. Study of the microstructure of a gold-coated pellet by scanning electron microscopy (SEM) showed that the sample has well-defined grains that are distributed uniformly throughout the surface of the sample. Detailed studies showed that the dielectric parameters (e r and tan δ) of the compound at three different frequencies (10 kHz, 100 kHz, and 1000 kHz) are almost constant in the low-temperature region (from room temperature to about 200°C). An anomaly in the relative permittivity (e r) (∼357°C) suggests the possible existence of a ferroelectric–paraelectric phase transition of diffuse type in the material. Detailed studies of impedance and related parameters show that the electrical properties of the material are strongly dependent on temperature, showing good correlation with its microstructure. The bulk resistance (evaluated from impedance studies) is found to decrease with increasing temperature. This shows that the material has negative temperature coefficient of resistance (NTCR), similar to that of semiconductors. Studies of electric modulus indicate the presence of a hopping conduction mechanism in the system with nonexponential-type conductivity relaxation. The nature of the variation of the direct-current (dc) conductivity with temperature confirms the Arrhenius and NTCR behavior in the material. The alternating-current (ac) conductivity spectra show a typical signature of an ionic conducting system and are found to obey Jonscher’s universal power law.