PE Loop Research Articles

Sol-gel hydrothermal synthesis of lead-free BT nanoparticles for enhanced dielectric properties in PVDF nanocomposites

In the present work BaTiO3 nanoparticles (NPs) with different sizes from 150 to 400 nm were prepared by sol–gel hydrothermal method at a temperature lower than 220 °C, and were used as nanofiller for PVDF composites with a loading from 10 to 25 vol%. The morphology of the BT NPs was analyzed by Scanning Electron Microscopy (SEM), and the structural composition was studied by Raman spectroscopy and X-ray diffraction (XRD). The hydrothermal temperature was found to control both the size as well as the phase composition of the BT NPs.The PVDF/BT nanocomposites exhibit enhanced dielectric permittivity and reduced loss tangent, especially with 20 vol% NPs, which contributes to the improvement of the ferroelectric properties. The inclusion of BT in PVDF matrix enhances also the crystallinity of PVDF by acting as a nucleating agent, which further increases the stiffness of the composite. However, at higher volume loading, the reverse tendency was observed with a huge decrease in the PVDF crystallinity at 25 vol%. The simulated PE loop was also investigated for the different loadings mentioned above using an Ising type model based on a 2D lattice and solved by monte-Carlo metropolis method. The results are in good agreement with the experimental results for the polarization hysteresis loops.

Integrated structural and functional analysis of Ba1-xSrxTiO3-Bi0.5Na0.5TiO3 ceramics: Insights into energy storage and electrocaloric performance

This paper reports an extensive investigation on the structural, dielectric, ferroelectric and pyroelectric properties of 0.7Ba1-xSrxTiO3 – 0.3Bi0.5Na0.5TiO3 (x = 0.0, 0.5, 0.6, 0.7) ceramics synthesized via conventional solid-state reaction (SSR) technique. X-ray diffraction data confirms the presence of pure perovskite phase. The variation of lattice parameters with strontium concentration in 0.7Ba1-xSrxTiO3 – 0.3Bi0.5Na0.5TiO3 ceramics were evaluated using the Rietveld refinement of the XRD data. The variation of dielectric permittivity with temperature (ε' ∼ T) shows the diffused phase transition and all the parameters related to the relaxor ferroelectrics (relaxation coefficient, activation energy and freezing temperature) were evaluated. The energy storage properties of the as-prepared ceramics were evaluated using the room temperature PE loop. Amongst the as-prepared ceramics, the composition with x = 0.5 possesses the highest energy storage density of 0.46 J/cm3 with an efficiency of 90 %. The temperature dependent P-E loops were used to study the electrocaloric effect (ECE). The ECE calculations were performed using in-direct method based on Maxwell's thermodynamic relations. A maximum adiabatic temperature change of 0.32 K is achieved at 268 K under a small applied electric field of 25 kV/cm for the ceramic with Sr content x = 0.5. Additionally, electrocaloric responsivity ξmax = 0.13 K mm/kV was also found for the studied ceramics. The above results show that the ceramic 0.7Ba1-xSrxTiO3 – 0.3Bi0.5Na0.5TiO3 with the composition x = 0.5 is a viable lead-free option for application in solid state refrigeration.

Effect of sodium dodecyl sulfate on the dielectric and electrical properties of poly (vinylidene fluoride)-zinc ferrite composites

Polymer composites comprising Poly (vinylidene fluoride) (PVDF) as a matrix, Zinc Ferrite (ZnFe2O4: ZFO) as ceramic filler and Sodium Dodecyl Sulfate (SDS) as a surface modifying agent have been synthesized through a simple solvent casting route for application in energy storage devices. The Scanning Electron Microscopic (SEM) study confirmed that the surface modification through Sodium Dodecyl Sulphate improved the dispersion of ZFO particles in the PVDF matrix. The FTIR Spectrophotometer study revealed the existence of expected functional groups in the modified composites The advantage of treatment of SDS on the composite obtained from blending of PVDF with Zinc Ferrite was investigated. The Impedance Analyzer study indicated that the composite with 1.5 wt.% Zinc Ferrite nanoparticles encapsulated by SDS exhibited the highest dielectric constant and reduced loss tangent. In addition, the experimental values of the dielectric constant were compared with some theoretical models. Further, the PE loop study showed higher remanent polarisation in the 1.5 wt.% SDS treated composite indicating that treatment of SDS on Zinc Ferrite (ZFO) can be adopted to fabricate composites for high energy storage applications.

Structural, dielectric and electrical properties of (Ba0.95Zn0.05)(Ti0.95Sn0.05Se0.05)O3 ferroelectric ceramic

In this report, the proposed compound (Ba0.95Zn0.05)(Ti0.95Sn0.05Se0.05)O3 is synthesized by mixed oxide route for the extensive study of the dielectric and electrical properties. The crystallization, symmetry, structure (tetragonal), space group (P4mm), and lattice parameters were confirmed by an X-ray diffraction study. The dielectric and electrical properties in a wide range of temperatures and frequencies of this particular composition deduce various interesting properties on high dielectric permittivity, low tangent loss, relaxation mechanism, non-Debye type conduction, and negative temperature coefficient of resistance. From the frequency and temperature dependence, dielectric loss shows a very low loss factor (<0.06) at low temperatures (<250 °C). Nyquist plots discuss the contribution of grain and grain boundary by fitting it with the help of the software ZSimpWin. The PE loop measurement showed that the corresponding hysteresis had main parameters for (Ba0.95Zn0.05)(Ti0.95Sn0.05Se0.05)O3 compound, remnant polarization (Pr = 0.28 µC/cm2) and coercive field (Ec = 1.35 kV/cm). All the above characteristics conclude that it may be applicable in electronic device industries.

Synthesis and characterization of lead free multidoped ferroelectric material: (Bi0.85Nd0.15)(Fe0.5Ti0.5)O3

The Nd and Ti doped bismuth ferrite compound (Bi0.85Nd0.15)(Fe0.5Ti0.5)O3 has been synthesized through a solid state reaction method. Its various properties, such as structural, dielectric and ferroelectric features were thoroughly investigated. The XRD analysis confirms the phase formation with monoclinic symmetry of the compound. The field effect scanning electron microscope (FE-SEM) micrograph/image shows the surface morphology and uniformly distributed grains over its surface. Energy dispersive X-ray (EDX) suggests the presence of all ingredients with appropriate purity (constituent elements are in well ratios of their atomic and weight percentage). Investigation of impedance and dielectric data was carried out in an extensive range of temperature and frequency. Prepared material data expose a significant improvement in the electrical and dielectric characteristics. Frequency dependent ac-conductivity diagram/plot of present material obeys Jonscher’s universal power law. The PE loop tracer study confirms the ferroelectric nature of the material. Present study offers several interesting features of the material for further device applications.

Extension of Surface Charge Density Studies of Metal Oxide Semiconductor (MOS) Structure to Polarization Studies of Metal Ferroelectric Metal (MFM) Structure in Bulk Form: Experimental and Simulation of Polarization Data

Ba(NdxTi(1-2x)Nbx)O3 and (Na0.5Bi0.5)(NdyTi1-2yNby)O3 relaxor ferroelectric materials were prepared through solid state sintering route. The polarization as a function of electric field (PE loops) were measured with Radiant technologies PE loop tracer. In the present studies we have extended the surface charge density studies of metal oxide semiconductor (MOS) structure to the polarization studies of metal ferroelectric and metal (MFM) structure in bulk form by combining it with the modified Glazounov and Arrhenius equations. The simulation is in good agreement the experimental data. In the case of Ba(NdxTi(1-2x)Nbx)O3 ceramics the value of dipole moment (p) are 2.24x10−26 C.m, 1.80x10−26 C.m, 2.23x10−26 C.m & 2.21x 10−26 C.m for x = 0.025, 0.05, 0.1 & 0.2, respectively. The values of surface potential (Ψp) are 466 meV, 503 meV, 552 meV & 505 meV for x = 0.025, 0.05, 0.1 & 0.2, respectively.

Tuning of efficient energy storage and fast switching capability in La2Zr2O7 pyrochlore nanoparticles mediated by Gd-substitution

Electrostatic capacitors are widely investigated to fulfill the energy storage demand and their utilization in microelectronic devices. The efficient energy storage capabilities of pyrochlores with less loss factor make them eminent in energy storage contesters. Here we synthesized a series of La2-xGdxZr2O7 with x = 0.0, 0.4, 0.8, 1.2, 1.6, and 2.0 substitution contents via the sol-gel auto-combustion process. The substitution of Gd on the La site compresses the pyrochlore structure without any phase transformation which leads to an increase in the X-ray density. A gradual decrease in grain size with an increase in substitution contents causes the increase in surface adhesion and agglomeration. Energy-dispersive X-ray spectra confirm the formation of exact compositions for all the samples. The energy storage capability of the synthesized series is examined by the PE loop, leakage current, PUND sequence, and normalized capacitance. An increase in energy storage abilities is noted with an increase in Gd concentration. The small value of energy loss, the highest recoverable energy density with a larger value of effective and normalized capacitance is recorded for Gd1.6La0.4Zr2O7 composition which exposed the potential of this composition for microelectronics devices to fulfill the energy storage demand.

Ferroelectric and Magnetic Optimization of A-Site La-Substitution in Bismuth Ferrite

La-substituted Bismuth ferrite, with the chemical composition Bi1-xLaxFeO3 (with x = 0.0, 0.05, 0.10 and 0.15), were synthesized using Sol-gel technique and sintered at a relatively low temperature of 600 °C. XRD-spectra confirmed the formation of rhombohedrally distorted perovskite phase up to x = 0.10 and the presence of peaks corresponding to orthorhombic perovskite phase of LaFeO3 at x = 0.15. PE loop shows the polarization behavior of the prepared samples. Studies of dielectric constants and dielectric loss factors were also carried out. La-substitution of x = 0.05 shows optimum saturation and remanent magnetization. Possible mechanisms explaining the various trends of the different properties are being discussed.

Study of microstructural, ferroelectric and magnetic properties of cerium substituted magnesium ferrite and its potential application as hydroelectric cell

This paper presents the synthesis of rare-earth doped magnesium ferrite, CexMgFe2-xO4 (where x = 0, 0.05, 0.10) by using co-precipitation process. X-ray diffraction analysis revealed the phase purity of the synthesized material. Refinement of XRD data using Rietveld suggested single phase spinel cubic formation of CexMgFe2-xO4 (where x = 0, 0.05, 0.10). The crystallite size was found to be in the range of 24–29 nm, obtained by using Scherrer's formula. SEM micrographs show the spherical particles agglomerated with cubic-shaped particles. Electron dispersive spectroscopic peaks indicate the purity of the samples with the concentration of the constituent elements in the expected range. Fourier transform infrared spectra contain two intrinsic vibrational peaks (ν1 and ν2) in the characteristic region, which may be attributed to the presence of tetrahedral group (A-site) and octahedral group at B-site in the ferrite material. Raman spectral analysis further validates the results obtained from FTIR and XRD peak analysis. The presence of well-defined polarization loops in PE loop analysis reflects the ferroelectric behavior of the synthesized samples. The ferroelectric behavior increases with an increase in Ce-doping. Magnetic studies of the synthesized samples were carried out by VSM, which depict the soft magnetic behavior of both pristine and doped samples. Magnesium ferrite was doped with Ce to create a defective structure that may be used to generate hydroelectricity. These defects produced compressive strain in these materials, confirmed by Williamson-Hall (WH) plot. These defected sites, along with oxygen vacancies present in the ferrite material, lead to water dissociation on its surface. After channelizing the dissociated ions through electrodes, these Ce-based HECs generated a maximum offload current of 5.2 mA and 8.4 mA for CexMgFe2-xO4 (CMF-1) and CexMgFe2-xO4 (CMF-2) cells with open circuit voltage of 0.86 V and 0.76 V respectively.

Unified Thermal System Simulations of an Electric Truck

&lt;div class="section abstract"&gt;&lt;div class="htmlview paragraph"&gt;Effective thermal management of an EV becomes a complex and yet essential topic due to strong dependence of electric powertrain performance on the thermal system performance. Once the powertrain sizing is decided for any new EV, electric vehicle thermal management is major challenge and opportunity to improve on overall energy efficiency. This is more pertinent in the context of a commercial vehicle where range is of utmost importance. A novel approach is proposed hereby to integrate different interfacing systems &amp;amp; subsystems of a vehicle that play a critical role for determination of thermal system sizing. This includes starting from vehicle model, electric powertrain (ePT) HVAC and cooling systems and simulate these in one environment under different scenarios as per customer expectations. A simplified controller is designed and integrated to monitor and control the functioning of such thermal systems for &lt;span class="strike-through"&gt;desired&lt;/span&gt; performance.&lt;/div&gt;&lt;div class="htmlview paragraph"&gt;Transient simulations are performed to mimic real world routes to analyze and select right under-hood module over a range of different ambient conditions. Commercial software namely GT is used for flow and thermal modelling and Simulink is used for power electric models and controller. Iterative process is established to arrive at right combination of radiators, fan, pump and compressor size along with optimum controller actuation to regulate the events of heat exchange meeting all thermal marginal limits of Battery &amp;amp; PE loop components. The method is being extended to evaluate different thermal concepts through different thermal architecture.&lt;/div&gt;&lt;/div&gt;

Role of phonon mode in the enhancement of ferroelectric polarization in a perovskite-based eco-friendly functional material

We report here the role of component freezing of three-dimensional polar () phonon mode corresponding to the center of cubic Brillouin zone in tuning the structure-property correlations of a scientifically enriched and technologically important barium-titanate–based eco-friendly functional material (Ba0.92Ca0.08)(Zr0.05Ti0.95−x Sn x )O3; BCZTSnx synthesized via solid-state reaction method. The combined X-ray diffraction, Raman spectroscopic analysis, and temperature-dependent dielectric studies have revealed the presence of several crystallographic phase transitions with coexisting phases, viz., , as a function of Sn(x) content. These crystallographic phases, viz., P4mm, Amm2, and R3m results due to freezing of the component(s) of phonon mode (belonging to space group), with the respective order parameter directions (0,0,a), (a,a,0), and (a,a,a) leading to ferroelectric polarization along , and directions, respectively. The ceramic composition corresponding to exhibits a significant reduction in the coercive field (E c ) and an enhancement in ferroelectric polarization (P r ) in comparison to , inferred from PE loop measurements. The enhancement in ferroelectric polarization at has been attributed to the inter-ferroelectric three-phase coexistence around this composition and significantly enhanced amplitudes of ferroelectric phonon modes corresponding to orthorhombic and rhombohedral phases, calculated using the symmetry mode analysis technique. The existence of a high ferroelectric polarization and low coercive field may lead to composition as an eco-friendly candidate for ferroelectric memory devices.

Synthesis and characterization of new multiferroic (BiBa)(FeTi2)O8

The present communication reports the study of various properties (i.e., structural, electrical, dielectric, ferroelectric, and magnetic) of new multiferroic: (BiBa)(FeTi2)O8 synthesized by a mixed oxide reaction route. The analysis of the X-ray diffraction profile at room temperature ensures its phase formation in the orthorhombic crystal structure. The micrographic study divulges irregular shape grains (mostly rectangular) with an average grain size of 3.5 μm. The compositional study displays the desired stoichiometry. The study of electrical (impedance, modulus, and conductivity) and dielectric properties (dielectric constant and tangent loss) of the sample at different temperatures (RT – 773 K) and electric field frequency (1 kHz-1MHz) provides many new experimental data, and insight mechanisms. The temperature dependence of the dielectric constant exhibits a dielectric anomaly around 523 K that may be due to the combined effect of oxygen vacancy mediated redox reaction (Fe3+→Fe2+ and Ti4+→Ti3+) and Maxwell-Wagner polarization. The loss tangent follows a similar trend to that of the dielectric constant except for an additional low-frequency relaxation peak of about 543 K. The dielectric loss tangent exhibits low value in low temperature and high-frequency regions, indicating that the sample can be a potential candidate for data storage devices. The ferroelectric recording shows a non-linear PE loop at room temperature. The room temperature magnetic recordings show evidence of weak ferromagnetism due to suppression of spiral spin structure as opposed to the antiferromagnetic nature of BiFeO3. The coexistence of these unique features enables the synthesized sample to be used in voltage-controlled data storage devices.

Key role of tetragonality in the enhancement of ferroic response of modified Ba0.85Sr0.15Zr0.1Ti0.9O3

We examine the correlation of tetragonality factor and underlying ferroelectric response via performing B-site doping, more competent in comparison to A-site. B-site doping opens a route toward optimization of various physical parameters via promoting the off-centering of central ions. Here, we provide detailed investigation of the effect of doping in Ba0.85Sr0.15Zr0.1Ti0.9O3 (BSZT) modified with x wt. % CdO (x = 0, 1, 2) ceramics. Room temperature structural analysis emphasizes that tetragonality of the BSZT system increases with doping, which results in a realization of large spontaneous polarization and pinched PE loop by providing additional octahedral voids to move B-site cations. Additionally, Cd doping strengthens the anomaly in the Pyroelectric coefficient. This results in significant improvement in electrocaloric response and pyroelectric figure of merits. The electrocaloric response at ambient temperature enhances from 0.45 (x = 0%) to 0.69 J/Kg-K (x = 2%) ceramic. Cd doping improves energy storage efficiency and is found to be 61% (x = 0%) and 83% (x = 2%). A considerable change in the pyroelectric figure of merit is observed. Our study reveals that manipulation of tetragonality seems a suitable strategic route for developing effective pyroelectric and energy storage materials.

Optical properties, dielectric relaxor behavior, impedance and modulus spectroscopy of 0.8BiFeO3-0.2CaTiO3 composite

0.8BiFeO3-0.2CaTiO3 (0.8BFO-0.2CTO) was synthesized by the sol-gel route. Structural characterization was performed by X-ray diffraction which confirms the rhombohedral structure. FESEM analysis reveals the irregular grains that are inhomogenous and slightly dense. Temperature-dependent dielectric permittivity shows a dielectric anomaly near the magnetic phase transition temperature (TN) of BiFeO3 as well as relaxor-type ferroelectric properties. The PE loop confirms the presence of ferroelectricity in the sample. Frequency-dependent ac conductivity exhibits low frequency dispersion and was well explained by Jonscher power law. The obtained fitting parameters A (pre-exponential factor that indicates polarizability) and n (dimensionless frequency exponent) show maxima and minima at the transition temperature. The electrical properties were further analysed by impedance and modulus spectroscopy. According to these analysis, the relaxation time was distributed and does not follow the Debye type behaviour. Nyquist plots had been used to estimate grain and grain boundary contributions. A typical negative temperature coefficient of resistance (NTCR) behaviour was apparent due to the decrement in bulk and grain boundary resistances as the temperature increases. The temperature-dependent relaxation time revealed Arrhenius's behaviour. 0.8BFO-0.2CTO exhibits absorption and shows a transmittance of 40–44% in the visible region of spectra. The obtained value of Eg was ∼2.26 eV, which implies the application in ultrafast optoelectronic devices. The good ability of absorption in visible region, high transmittance, the increase of extinction coefficient with wavelength, and low band gap makes 0.8BFO-0.2CTO an extraordinary material for optical devices application. The sample also shows a decrease in magneto-capacitance and increase in magneto-impedance which reflects the presence of strong magneto dielectric coupling in 0.8BFO-0.2CTO at room temperature.

Structural and Electrical Characteristics of FeTiVO6 Double Perovskite

In this paper, studies of structural as well as electrical characteristics of the double perovskite material FeTiVO6 (iron titanium vanadate), synthesized by a high-temperature mixed oxide reaction method have been discussed. The room temperature X-ray diffraction analysis confirms the formation of a single-phase orthorhombic structure without any secondary phase. All the electrical characteristics (i.e., dielectric, impedance, conductivity and modulus) of the sample, studied at various temperatures (25–300°C) and frequencies (1[Formula: see text]kHz–1[Formula: see text]MHz), provide many remarkable characteristics of the material. The dielectric parameters as a function of frequency explain the presence of different polarization mechanisms based on the Maxwell–Wagner double-layer model. Impedance analysis describes the grain (bulk) and grain boundary (bulk interior) effect on the material using the equivalent RQC-RC circuits. The presence of non-Debye type of relaxation behavior in the material is confirmed by the depressed semicircles of Nyquist plots. The conductivity study provides information about the CBH and OLPT type of conduction phenomenon. The temperature dependence of leakage current behavior follows the Ohmic (semiconductor) and space charge limited conduction mechanisms at a different range of applied fields. The occurrence of the room temperature hysteresis loop obtained from the PE loop tracer confirms the ferroelectric behavior of the studied compound.

Relaxor ferroelectricity driven by ‘A’ and ‘B’ site off-centered displacements in cubic phase with Pmm space group

The present report leads to the development of a lead-free perovskite system (BaCa)(Sn0.11Zr0.05Ti0.84)O3 (BCSZTx); 00.20, exhibiting relaxor ferroelectric behaviour in an average cubic structure. The x-ray diffraction measurements have shown a simple cubic phase with Pmm space group for all the compositions. Despite having a centrosymmetric cubic phase, a slim hysteresis loop has been observed via PE loop measurements. Raman spectroscopic measurements have revealed the presence of local ordering in the macroscopic cubic matrix, corresponding to ‘A’ and ‘B’ sites. The cooperative behaviour of ‘A’ and ‘B’ site off-centered (local) atoms leading to microscopic polar symmetry in the macroscopically cubic matrix is held responsible for the observed relaxor ferroelectric nature. Owing to the aforementioned contrapositive behaviour, these ceramics have exhibited a high value of dielectric constant. Eventually, we have clearly observed a decisive role of Ca2+ dopant at ‘A’ site in BCSZTx ceramic system leading to the enhancement in the relaxor ferroelectric behaviour and dielectric properties. The presence of a slim hysteresis loop along with broad and diffuse dielectric nature makes these ceramics, a potential candidate for energy storage applications.

Structural Evolution and Enhanced Energy Density, Ferroelectric Property Investigation in Gd Substituted NBT – BT Lead Free Ferroelectric Ceramics

Gd substituted 0.94(Na0.5Bi0.5-xGdxTiO3) – 0.06 BaTiO3 (x = 0.00, 0.01, 0.02 and 0.03) lead free ferroelectric ceramics were synthesized by a conventional solid-state synthesis. Room temperature XRD reveals the formation of perovskite structure without secondary impurity peaks. Rietveld refinement pattern confirms the coexistence of dual phase i.e., major monoclinic (Cc) and minor tetragonal (P4mm). More tetragonality and slim ferroelectric properties were noted with increasing Gd content in NBT-BT solid solutions. A collective Gd substitution stimulates the transition of PE loop shape from square to slim with slanted leads to suit for high energy density storage applications. The optimum energy storage properties can be achieved for x = 0.03 ceramic showed a recoverable energy density 1.59 J/cm3 and a remarkably best energy efficiency of 67% under 65 kV/cm at room temperature.

Investigations on structural, optical, high temperature electrical and ferroelectric properties of Neodymium doped rubidium titanyl phosphate single crystal

Neodymium doped Rubidium Titanyl Phosphate (RTP) single crystal was grown using a high-temperature flux solution method with rubidium polyphosphate flux. Though doping does not induce changes in growth temperature, variations in material properties were observed while characterizing the grown crystal. Powder x-ray diffraction and high resolution x-ray diffraction analysis of Nd: RTP single crystal suggested the orthorhombic structure with small structural distortion and good crystalline nature. The presence of neodymium and other elements in the crystal was confirmed using EDAX analysis. The optical quality of the material was studied using optical transmittance and absorption studies. The variation in the optical band gap due to Nd doping was also analyzed. The dielectric polarization, ion hopping, activation processes, dielectric, electrical conductivity, and resistivity nature of the grown crystal were studied using impedance analysis. The properties were studied from room temperature to 850 °C, in the frequencies range from 100 Hz to 8 MHz. Then the results were compared with flux-grown pure RTP single crystals. The result exhibited superior properties on Nd doping in RTP. The low and static dielectric constant exhibited by Nd: RTP made it suitable for NLO applications. The ferroelectric nature of the Nd: RTP was analyzed from room temperature to 180 °C at an applied field of 4 kV and the PE loop was found with values of polarization and coercive field as 0.15 μC/cm2 and 1.79 kV/cm, respectively. Nd: RTP does not show any polarization decay up to 5000 frequency cycles confirmed by fatigue analysis.

Influence of electric and magnetic poling on properties of Co/Nb codoped cobalt ferrite

Nb doped CoFe2O4 ferrites (Denoted: Co1.2Fe1.7Nb0.1O4) was prepared by conventional solid state reaction method at calcination temperature 1300 ͦ C. The tuning of both electrical and magnetic poling on the prepared samples shows suppression of (111) peak as observed in X-ray diffraction study implying that (111) is the easy magnetic axis in polycrystalline cobalt ferrite and it responds to both electric and magnetic field. Furthermore, the strain derivative of 84 × 10−9 Oe−1 at a field of 790 Oe is observed from magnetostriction measurement. Converse magnetoelectric effect was observed on an electrically poled sample where the sample got magnetized upon electrical poling. The value of linear magnetoelectric coefficient obtained was 150 mV/cm.Oe which is unusually high for a single phase material and at room temperature and this may be due to the d0 configuration of Nb. The observed linear magnetoelectric coefficient and room temperature PE loop was obtained suggesting that the Co1.2Fe1.7Nb0.1O4 material could be useful for magnetoelectric sensor applications.

Structure, dielectricity and ferroelectricity measurement of new perovskite ceramics (1-x)BaTiO3-xBiMnO3 synthesized by solid-state reaction

The complex oxide of general form (1-x)BaTiO3-xBiMnO3 was synthesized by solid-state reaction route and characterized the structure, dielectricity, and ferroelectricity for the first time. The XRD pattern confirms the formation of perovskite structure and a phase transitions from the tetragonal to cubic phase corresponds to the composition x > 0.3 with a reasonable change in the lattice parameter. An optimum dielectric constant value of 14512 corresponds to a maximum temperature of 200 °C, and 100Hz frequency has been measured in 0.5BaTiO3-0.5BiMnO3 ceramic. In contrast, the PE-loop study of these ceramics exhibited a remanent polarization (Pr) 0.230 μC/cm2 at a coercive field electric field (Ec) of 2.8 kV/cm in 50BaTiO3–50BiMnO3 ceramic. The composition-dependent change in structure and properties shows a prospective existence of morphotropic phase boundary (MPB) at about the composition with x = 0.5. The typical dielectricity and PE loop measurement of the oxides, especially in the composition range with x = 0.1 to 0.5, seems to be promising materials for multilayer ceramic capacitor (MLCC) and device applications.