Standard Solid-state Reaction Research Articles

Low permittivity MgF2-LiF ceramics with ultra-low dielectric loss for ULTCC applications

In this work, MgF2–xwt%LiF (x = 0.5, 1.0, 2.5, 4.0, 5.0) ceramics have been prepared through the standard solid-state reaction method. X-ray diffraction patterns and scanning electron micrographs revealed the successful preparation of dense MgF2–LiF composite ceramics at an exceptionally low sintering temperature range of 525–600°C. The optimal microwave dielectric properties (εr = 5.09 ± 0.03, Qf = 100,733 ± 1646 GHz, τf = −67.4 ± 3.3 ppm/°C) were achieved in MgF2–0.5 wt%LiF ceramics after sintering at 550 °C for 3 h. The present ceramics exhibited an outstanding combination of low-εr, high Qf, and an ultra-low sintering temperature, surpassing the performance of most low-temperature-fired dielectric materials. Moreover, the theoretical Qf value, extrapolated from the fitting of infrared reflectivity spectra, was calculated to be 326,583 GHz, indicating significant potential for further Qf improvement. Additionally, the chemical compatibility with Al electrodes was confirmed, suggesting promising potential for ultra-low temperature co-fired ceramic (ULTCC) applications.

Unveiling the Structural and Optical Properties of Samarium Titanates Pyrochlore, Sm2Ti2O7

A magnetic system whose geometry prevents all pairwise spin interactions from being fulfilled simultaneously to minimize the energy is said to be frustrated. These systems are prevalent throughout all disciplines of physical and chemical study. This article reports a detailed structural and optical analysis of such frustrated Sm2Ti2O7 (STO), a pyrochlore structure. The ordered pyrochlore, STO of cubic symmetry, space group Fd3¯m [no. 227], has been synthesized using the standard solid-state reaction method. The Tauc’s plot reveals a direct band gap value of 3.8 eV from ultraviolet-visible reflectance data. Photoluminescence studies for STO using 280 nm excitation wavelength show the most intense emission peak at 395 nm, 468 nm, and other weak emissions at 368 nm, 412 nm, 430 nm, 449 nm, and 514 nm corresponding to the respective electronic transitions, indicates that the materials show photoluminescence properties. However, the unique characteristics of Sm2Ti2O7, including its wide band gap, photoluminescence, and high refractive index, make it a promising candidate for various magneto-optical, solid oxide fuel cell device fabrication applications.

Improved relaxor ferroelectrics and energy storage performance of polycrystalline Ba0.95Sr0.05Ti2O5 ceramics modified with La dopants

Lead-free relaxor ferroelectrics are useful in energy storage applications. In particular, BaTi2O5-based dielectric materials may have great potential for such applications. In this study, polycrystalline Ba0.95Sr0.05Ti2O5-xLa (BST2-xLa) ceramics were synthesized using a standard solid-state reaction method with as-prepared nanoparticles prepared via a modified Pechini polymeric precursor method. The structural and electrical properties of the BST2-xLa ceramics were systematically investigated using a series of measurements. The phase analysis results confirm that La3+ is a donor dopant that replaced Ba2+ sites in the structure, which results in a decrease in oxygen vacancies to maintain charge neutrality. The intrinsic electronic conduction mechanism for electrical conductivity was evaluated from the fitted activation energy based on the Arrhenius equation. The relaxor ferroelectric behaviour and energy storage density and efficiency are improved by the addition of a small amount of lanthanum (<3.6 mol%) because of the charge and ionic radius mismatch in the structure. These results suggest that lanthanum can effectively optimise the relaxor ferroelectrics of BST2-xLa ceramics, which have promising potential as energy storage materials.

Near room temperature hexagonal multiferroic (Yb0.25Lu0.25In0.25Sc0.25)FeO3 high-entropy ceramics

In this work, h-RFeO3 multiferroic high-entropy ceramics are designed by introducing high-entropy concept with four elements (Yb, Lu, In, Sc) for R site. (Yb0.25Lu0.25In0.25Sc0.25)FeO3 high-entropy ceramics are prepared by the standard solid-state reaction methods. The samples prepared with precursors were identified to crystalize in the pure hexagonal structure with polar space group (P63cm) at room temperature. By the analysis of the variable XRD patterns, it is speculated that the ferroelectric transition temperature of the sample is above 773 K. Meanwhile, three magnetic anomalies are determined for high-entropy ceramics, which is the antiferromagnetic transition at Néel temperature TÑ280 K, the spin-reorientation temperature TSR∼145 K and the reasonable ferromagnetic-like clusters without long ordering in TN < T < TA (∼397 K). Besides, it is observed that the peak intensity of the pyroelectric current around TN can be tuned by magnetic field, which is indicated the magnetoelectric coupling effect in (Yb0.25Lu0.25In0.25Sc0.25)FeO3 high-entropy ceramics. These results indicate the ferroelectric and antiferromagnetic orders are coexist in the h-RFeO3 high-entropy ceramics as promising near room temperature multiferroic materials, and it is an effective way to obtain a new type single-phase multiferroic materials.

Ca/Sn concentration-dependent enhancement of barium titanate ferroelectric performance: a dielectric and microstructural study

This work involved the synthesis of compositions of Ba0.95Ca0.05SnxTi1-xO3 (BCST) with varying amounts of Sn dopant (x = 0, 0.02, 0.04, 0.06, 0.08, and 0.1). A standard solid-state reaction approach was used to create all of the ceramic compounds. Each BCST composite’s microstructure, sintering, morphology, density, optical, and electrical characteristics were carefully examined, and the dielectric performance was optimized. In comparison to the unmodified composite, introducing varied amounts of Sn material into the BCST compound changed the crystal lattice vibrations and functional group locations. This result indicates that there are some variations in unit cell size, revealing that Sn+4 ions diffused effectively inside the lattice structure to produce BSCT composites. Further, SEM micrographs indicated proportionate changes in the homogenous structure and irregular forms as Sn concentration increased, as well as some variation in average grain size. As a consequence, by adding 0.08 mol% of Sn dopant, the crystallite size and average grain size were adjusted to 45.69 nm and 0.66 µm, respectively. Meanwhile, the 0.08-Sn specimen displayed a dielectric constant (Ɛ) with an optimum value of 5557 and a relative decrease in the Curie-Weiss constant. These results are attributed to the existence of various concentrations of Sn ions at the Ti-site of the BCT, which resulted in a compositionally disordered state. This disordered condition is essential for the production of dielectric compounds. Therefore, it is evident that modifying the amount of Sn doping added significantly enhanced the dielectric characteristics of the BCST composites created in this work. However, excessive Sn doping reduces the dielectric properties due to a reduction in tetragonal phase and an increase of disorders and charge fluctuations.Graphical

LiGaSiO4: An ultra-low permittivity dielectric material enabling application in patch antenna

A low permittivity microwave dielectric ceramic, Li-containing silicate (LiGaSiO4), was synthesized using the standard solid-state reaction method. The nominal LiGaSiO4 ceramic exhibited a relative permittivity of approximately 4.4. The effects of nonstoichiometric Li on the microstructure, sintering behavior, and microwave dielectric properties of LiGaSiO4 were comprehensively investigated. Excess Li content (6 mol%) significantly improved the relative density (96.1 %) and microwave dielectric properties (εr∼5.34, Q × f ∼55,600 GHz, and τf ∼ -48.6 ppm/°C), while reducing the optimum sintering temperature from 1070 °C to ∼1010 °C. Additionally, the incorporation of 2 wt% LiF further reduced densification temperature (∼940 °C). The regulation of the τf was achieved through the addition of CaTiO3 ceramic, and a patch antenna was designed and fabricated using a modified Li1.06GaSiO4-LiF-CaTiO3 composite ceramic. The resulting patch antenna resonates at 5.87 GHz with an impressive bandwidth of 83.1 MHz, while both simulated and measured results demonstrate excellent agreement.

Impact of hair-derived carbon substitution on structural and superconducting properties of MgB2

This study presents a comprehensive analysis of the effects resulting from the substitution of biowaste-derived carbon-dot (CD) from human hair on structural and superconducting properties of MgB2. Syntheses of polycrystalline samples were accomplished through a standard solid-state reaction route. X-ray powder diffraction results confirm the formation of MgB2 as a primary phase in all samples and show the successful substitution of carbon for boron in MgB2. The critical current density, determined at 20 K and 4.5 T, for carbon-substituted MgB2 synthesized at 850 °C was enhanced by more than four times compared with unsubstituted MgB2. The observed improvement is due to the formation of efficient pinning centers resulting from the incorporation of carbon substituting for boron in MgB2. Furthermore, x-ray photoelectron spectroscopy (XPS) confirmed the presence of carbon bonding to boron in MgB2 synthesized with biowaste-derived CDs, indicating successful incorporation into the structure. Ultraviolet photoelectron spectroscopy (UPS) results show that the carbon-substituted MgB2 can lead to changes in the electronic band structure and values of work function. These changes significantly impact the properties of MgB2 materials, including superconducting transition temperature, upper critical field, and critical current density. The XPS and UPS experimental results are in good agreement with density functional theory calculations for MgB2 with and without carbon substitution.

Fabrication and physical characteristics of K/W double doped BiFeO3 complex electro-ceramic; (Bi1/2K1/2)(Fe1/2W1/2)O3

The main objective of this research work is to investigate the effect of the inclusion of potassium/tungsten (K/W) (at the Bi/Fe site) on the structural, dielectric, electrical, and optical characteristics of eco-friendly BiFeO3 to assess its potential use for multifunctional applications including energy storage. The standard solid-state reaction method was used to synthesize the desired (Bi1/2K1/2)(Fe1/2W1/2)O3 complex compound. Examination of X-ray diffraction data demonstrates the structural transformation of bismuth ferrite from rhombohedral to monoclinic on the addition of K/W. The estimated crystallite size is 52 nm. The standard cell parameters include a = 12.1967 Å, b = 9.0468 Å, c = 6.4971 Å, and β = 105.02°, resulting in a cell volume of 692.40 Å3. Analysis of Raman spectra reveals a slight alteration in intensity and displacement of Raman mode positions, attributed to the doping effect, which confirms the incorporation of K and W ions into the BiFeO3 lattice. Scanning electron microscopy provides an image indicating the dense surface structure of the sample. Elemental analysis through energy-dispersive X-ray spectroscopy verifies the presence and purity of the constituent elements. The material doped with potassium and tungsten exhibits a high dielectric constant (εr ∼ 3 × 103) and low tangent loss (tanδ ∼1). The extensive dielectric studies conducted across various frequencies and temperatures suggest that the sample possesses capacitive properties. The depression angle of 8.51° reflects the extent of deviation from Debye's behavior. The presence of hysteresis loops indicates the presence of ferroelectric behavior.

Vanadium Pentoxide Nanoparticles Doped ZnO: Physicochemical, Optical, Dielectric, and Photocatalytic Properties

In this work, vanadium pentoxide nanoparticles (V2O5) derived by the chemical coprecipitation route were used to synthesize various vanadium-doped ZnO nanocomposite samples via the standard solid-state reaction process. The effect of V2O5 nanoparticles on the physicochemical properties of ZnO was discussed. The prepared samples were characterized by X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy combined with energy-dispersive spectroscopy, and UV-visible spectroscopy. A diffuse reflectance spectroscopic approach is described to determine the bandgap energy (Eg) of the samples. The dielectric and photocatalytic characteristics are also examined. The photocatalytic performance of the prepared materials was tested under visible light using methylene blue (MB) as a pollutant dye model. As a result, it is found that the addition of V2O5 enhances the photodegradation of MB. The kinetics of the photodegradation reaction was found to follow a pseudo-first-order model.

Crystal structure and magnetization reversal in single-layered Ruddlesden–Popper CaEuFeO4 ceramics

Magnetization reversal widely exists in ferrimagnets, which provides an opportunity to develop novel low-power-consumption memory in the future. In the present work, dense CaEuFeO4 ceramics with the single-layered Ruddlesden–Popper structure were prepared by a standard solid-state reaction process. The orthorhombic phase was determined to have the space group Bmab at room temperature. The antiferromagnetic state was observed below the Néel temperature of 338 K, and temperature-induced magnetization reversal was observed below the compensation temperature in the field cooling protocol. Moreover, field-induced magnetization reversal or bipolar magnetic switching between different fields was also observed at low temperatures. The intriguing temperature- and field-induced magnetization reversal is induced by the competition between the canted Fe3+ moment and the antiparallel Eu3+ moment induced by the Eu–Fe exchange interaction.

A novel narrow-band red-emitting multi-layer phosphor for white – Light emitting devices

SrZr2La2O7: Eu+3 (0.5–2.5 mol %) phosphors have been synthesized through the standard solid-state reaction technique. The photoluminescent and other structural properties such as PXRD (Powder X-ray Diffraction), SEM (Scanning Electron Microscopy) and Energy Dispersive X-ray spectroscopy (EDX), FTIR (Fourier transform infrared spectroscopy), PSD (Particle Size Distribution) of the phosphors were learned. The photoluminescence spectra show that the phosphor exhibited intense and dominant red emissions at 627 nm belonging to the 5D0 → 7F2 electric dipole transition. The FWHM of the red emissions at 627 nm is only 8.0 nm increasing in luminous efficacy. Hereby we propose a novel RED phosphor for RED emitting LEDs with phosphor-embedded polymer matrix layers of variable thickness and stacking up to 400 µm. The intensity of the red color was enhanced by self-excitation of photon absorption and emission. As a result, Eu3+doped SrZr2La2O7 phosphors can be widely used as red phosphors in UV chip-based WLEDs and displays. The phosphor exhibits high color purity up to 99% when excited at 590 nm. X-ray powder diffraction analysis confirms that the phosphor is highly crystalline and has a cubic phase.

Novel non-equimolar SrLa(Al0.25Zn0.125Mg0.125Ga0.25Ti0.25)O4 high-entropy ceramics with excellent mechanical and microwave dielectric properties

Novel non-equimolar high-entropy SrLa(Al0.25Zn0.125Mg0.125Ti0.25Ga0.25)O4 (SLAZMTG) ceramics with a layered perovskite structure have been prepared via the standard solid-state reaction method. The high-entropy composition belongs to the tetrahedral structure with a space group of I4/mmm, which is confirmed by the XRD and TEM analyses. Excellent microwave dielectric properties with a suitable dielectric constant (εr = 22.5), high quality factor (Qf = 83,003 GHz), and near-zero τf value of −1.7 ppm/°C are obtained in SLAZMTG ceramics sintered at 1400 °C. Meanwhile, a significant enhancement in compressive strength was achieved due to the improvement of configuration entropy, 912 MPa for SLAZMTG compared to 578 MPa in the pure SrLaAlO4 composition. Additionally, the high-entropy engineering in the present work suggests great potential in achieving low thermal conductivities. SLAZMTG ceramics exhibit low thermal conductivities ranging from 2.86 W/m•K at 323 K to 1.99 W/m•K at 673 K, much lower than those of SrLaAlO4 and other perovskite ceramics.

Structural, magnetic and ferroelectric properties of magnetoelectrically coupled xBa0.95Sr0.05TiO3-(1–x)BiFe0.90Sm0.10O3 ceramics

ABSTRACT The standard solid state reaction method was followed to synthesize the polycrystalline xBa0.95Sr0.05TiO3-(1–x)BiFe0.9Sm0.1O3 [xBST-(1–x)BFSmO, x = 0–0.35] ceramics. The XRD pattern revealed a structural transition of the prepared ceramics from rhombohedral to cubic symmetry. The mean grain size was estimated in the micrometer range, with values ranging from 0.40 to 1.95 μm. The maximum real part of the complex initial permeability of 28.26 was noticed for x = 0.30 multiferroic ceramics. The highest remanent magnetization determined for the x = 0.30 sample was 3.4 10−2 emu/g. For the sample with x = 0.35 the maximum recorded dielectric constant was found to be 677 at 103 Hz. A small value of dielectric loss (<5%) was observed. The compound exhibited significant remanent polarization and a reduction in the leakage current. In addition, the investigated materials comprise large magnetoelectric coefficients and the optimum magnetoelectric coefficient of 0.662 mV.cm−1.Oe−1was obtained for the x = 0.30 composition.

Studies of structural, dielectric, and electrical properties of polycrystalline barium bismuth tungstate for thermistor application

In this communication, preliminary investigation of structural and detailed analysis of electrical proprties of a new barium bismuth tungstate of a chemical composition Ba3Bi2WO9, produced via a standard high-temperature solid-state reaction method, is presented. The basic crystal structure of the compound is monoclinic (a = 8.4621 Å, b = 6.7358 Å, c = 6.9064 Å and β = 109.94°). The homogeneous distribution of grains (average grain size = 1.717 μm) is studied via surface morphology demonstrating the feasibility of fabricating a high-density sample under experimental conditions. This compound shows ferroelectric and related properties, which have been experimentally verified by examination of the frequency-temperature dependence of capacitance, impedance, and other related behaviors. The variation of ac conductivity of the material under alternating current varies according to Jonscher's universal power law. The ferroelectric property of the material (Pr = 0.331C/cm2, Ec = 0.207 kV/cm) is demonstrated by the electric field-dependent polarisation (P-E loop) study. The temperature dependence of resistance yields a thermistor constant (β) and temperature coefficient of resistance (TCR), which may be useful for fabricating thermistor-based device applications.

Tuning the magnetic and magnetoelectric response in Bi1-xYxFe0.7Mn0.3O3 multiferroics

Magnetoelectric (ME) coupling in multiferroic materials plays an important role in designing multifunctional devices because of their potential to tune polarization via a magnetic field or magnetism via an electric field. However, the single-phase ME materials have not been successfully explored in practical devices due to their low ME coupling coefficient. Here, we optimized the magnetic and magnetoelectric response of single-phase Bi1-xYxFe0.7Mn0.3O3 compounds by controlling the Y substitution and sintering temperature. Single-phase Bi1-xYxFe0.7Mn0.3O3 (where x varies from 0 to 0.20 in the step of 0.05) compounds were prepared by a standard solid-state reaction technique. The optimum sintering temperature and yttrium substitution were found to be 825 °C and x = 0.10, respectively, in which the sample shows the optimum microstructural, magnetic, and ME properties at room temperature. The optimized Bi0.9Y0.1Fe0.7Mn0.3O3 compound shows uniform growth of grains with less porosity, maximum remanent magnetization (∼0.012 emu/g), and enhanced ME coupling coefficient (35 mV/Oe.cm.). The ME coupling coefficient obtained from the optimized sample is six times higher than that of the pristine sample. This work provides a potential route for improving the ME coupling coefficient in BiFeO3-based multiferroic materials for practical applications.

Change in transition balance between durable tetragonal phase and stress-induced phase of cobalt surface-layered in Bi-2212 materials by semi-empirical mechanical models

This study has indicated the positive effect of sintering temperature on the mechanical durability, strength, critical stress, deformation degrees, durable tetragonal phase, failure and fracture by fatigue, and mechanical characteristic behavior to the applied test loads for the Co surface-layered Bi-2212 ceramic materials produced by the standard solid-state reaction method. The sintering mechanism has been used as the driving force for the penetration of cobalt ions in the Bi-2212 ceramic matrix. The microindentation hardness test measurements have been performed at the load intervals 0.245 N-2.940 N. The experimental findings have also been examined by the six different semi-empirical mechanical and indentation-induced cracking models. It has been found that all the mechanical performance parameters are improved considerably with increasing the diffusion sintering temperature up to 650 °C. On this basis, the Co surface-layered Bi-2212 sample produced at the sintering temperature of 650 °C has been observed to improve dramatically the mechanical durability and resistance to the applied test loads as a consequence of the formation of new force barrier regions, surface residual compressive stress regions, and slip systems in the Bi-2212 ceramic system. Similarly, the optimum sintering temperature has extensively enhanced the elastic recovery mechanism, critical stress values, and deformation degree levels, stored internal strain, and crack surface energy through the Bi-2212 ceramic materials. Accordingly, it has been noted that the best sample produced at 650 °C is more hardly broken than the other ceramics. Namely, the optimum sintering temperature has decreased the sensitivity to the applied test loads as a result of delaying the beginning of the plateau limit regions. On the other hand, all the mechanism has been found to reverse completely depending on the excess sintering temperature. Lastly, the indentation-induced cracking model has been found to exhibit the closest results to the original Vickers microhardness parameters in the plateau limit regions.

Novel high-entropy microwave dielectric ceramics Sr(La0.2Nd0.2Sm0.2Eu0.2Gd0.2)AlO4 with excellent temperature stability and mechanical properties

Novel high-entropy Sr(La0.2Nd0.2Sm0.2Eu0.2Gd0.2)AlO4 ceramics with a layered perovskite structure have been prepared via the standard solid-state reaction method. The design of high-entropy improves the bond valence and subsequently optimizes the large negative temperature coefficient of resonant frequency (τf = −32 ppm/°C) of the simple SrLaAlO4 ceramics. Excellent temperature stability (τf = −6 ppm/°C) together with a relative permittivity (εr) of 18.6 and a quality factor (Qf = 14,509 GHz) are obtained in Sr(La0.2Nd0.2Sm0.2Eu0.2Gd0.2)AlO4 ceramics sintered at 1475 °C. It indicates that the present ceramics have great application prospects in passive microwave components such as resonators and filters. Meanwhile, significant improvements in compressive strength and strain are achieved, which are 1040 MPa and 15.7% for Sr(La0.2Nd0.2Sm0.2Eu0.2Gd0.2)AlO4 compared to 583 MPa and 12% in SrLaAlO4. The enhanced mechanical properties originate from the dislocation strengthening mechanism as the intertwining of interlayer lattices is revealed from the high-resolution transmission electronic micrographs.

Study on Factors Hindering the Single-Phase Formation of Divalent-Ion-Stabilized W-Type Ferrites

Me-substituted W-type ferrites (AMe2Fe16O27 with A = Sr, Ba, …, and Me = Co, Ni, Zn, Mg, …) can be obtained by standard solid state reaction but always contain secondary phases. Phase stability of SrMe2Fe16O27 with Me = Co, Ni, Zn, and Mg sintered in various oxygen pressures of pO2 = 0.2, 1, 10, and 387 atm were investigated using X-ray diffraction analysis, wavelength dispersive X-ray (WDX) analysis, and transmission electron microscopy (TEM). WDX analysis revealed that the W-type ferrites are described as SrMe2−δFe16+δO27 because Fe3+ is partially reduced to Fe2+ even when synthesis is initiated from SrMe2Fe16O27. Increasing the oxygen pressure suppresses the reduction of Fe3+ and the formation of the secondary phases. In addition, TEM analysis shows that the SrCo2Fe16O27 single crystal is free of stacking faults. We conclude that the single-phase formation of the Me-substituted W-type ferrites is hampered by the discrepancy between initial and actual chemical composition caused by the appearance of Fe2+.

Effect of Ce4+→Ce3+ conversion on the structural and luminescence properties of Ce4+ doped Gd2Ti2O7 pyrochlore oxide

Ternary oxides with cerium oxide as dopant are now useful as blue chip for the production of WLED's. In this present work, pyrochlore oxides Gd2Ti2-xCexO7 with doping concentration x = 0, 0.04, 0.08, 0.12, and 0.16, were prepared through standard solid-state reaction route. A pyrochlore structured phase is formed in the synthesized series as confirmed by conventional techniques; i.e., X-ray diffraction and Raman spectroscopy. Both techniques were revealed a systematic unit cell expansion as a function of doping concentration. The SEM micrograph confirms the formation of spherically agglomerated micron sized grains. In the later section of the manuscript, Ce4+→Ce3+ conversion effect on structural and luminescent properties were investigated. A relatively larger amount of cell expansion and accumulation of the strain is observed in the pyrochlore structured reduced samples. X-ray photoelectron spectroscopic (XPS) was used to investigate the oxidation state of the Gd, and Ti cations and oxygen anion. PL excitation spectra showed two broad bands centered around 255 nm and 360 nm due to the 4f→5d transition of Ce3+ ions at λem = 425 nm. Moreover, PL emission spectrum shows a broad peak around 425 nm at λex = 360 nm due to the 5d to 2F7/2 and 2F5/2 transitions. We observed that for the Ce4+→Ce3+ conversion both the PL emission and excitation spectra give far better results as compared to unreduced samples. Concentration quenching effect was observed for the doping concentration of 4% of cerium dopant. For 4% doping of cerium ion, CIE chromaticity results showed that the reduced as well as unreduced samples produce a bright blue colored emission line. The present study provides an insight about the potential use of Ce4+→Ce3+: Gd2Ti2O7 to synthesize blue LED chips for the fabrication of WLED's.

Study of LaCoO3 Across Insulator–Metallic Phase Transition

The standard solid-state reaction method was used to prepare perovskite LaCoO3 crystal successfully. The crystal structure was confirmed by means of powder X-ray diffraction. An investigation of the electrical properties shows an interesting temperature dependence. The real and imaginary parts of the dielectric constant show maximum at 533 K and minimum at 548 K. This indicates an Insulating-Metallic phase transition. It was found that the activation energy \(\Delta E_{a}\) in the semiconducting region was about 0.80 eV. The grain resistance shows an inverse dependence on temperature justify negative temperature coefficient of resistance exhibit. The crystal exhibits non-Debye type dielectric relaxation.