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Multiferroic xBa0.95Sr0.05TiO3-(l-x)BiFe0.90Gd0.10O3 [xBST-(l-x)BFGO] (x = 0.00, 0.10 and 0.20) ceramics were prepared by the standard solid-state reaction technique. Crystal structure of the ceramics was determined by X-ray diffraction pattern. All the compositions exhibited rhombohedral crystal structure. The tolerance factor't' varied from 0.847 to 0.864. The AC conductivity spectrum followed the Jonscher's power law. The Nyquist plots indicated that only grains have the contribution to the resistance in this material and the values of grain resistance (Rg) increased with BST content. The real part of complex initial permeability decreased with the increase in frequency and increased with increasing BST content. Magnetoelectric coefficient was determined for all compositions. The maximum value of magnetoelectric coefficient was found to be 1.467 mV.cm -1.Oe-1 for x = 0.20. [ABSTRACT FROM AUTHOR]

In the present work, we have discussed the electrical transport properties of the polycrystalline NiCr2O4 by employing Impedance spectroscopy and DC resistivity techniques. It was observed that charge carriers follow Arrhenius type conduction throughout the temperature range. Activation energy (Ea) has been calculated from the impedance data, 0.462 for Rgb and 0.42 from Rg, which is well buttressed by the activation energy from the DC resistivity fitted data which is 0.468 eV. [ABSTRACT FROM AUTHOR]

We are reporting photosensitivity property of BiFeO3 thin film under optical illumination. The thin film used for photosensitivity work was fabricated via sol-gel assisted spin coating technique. I-V measurements on the Cu/BiFeO3/Al structure under dark condition show a good rectifying property and show dramatic blue shit in threshold voltage under optical illumination. The microstructure, morphology and elemental analysis of the films were characterized by using XRD, UV-Vis, FTIR, SEM and EDS. [ABSTRACT FROM AUTHOR]

Multiferroic 2-2 type layered NFO/ (Pb0.50Sr0.50) TiO3 composite thin film on Pt/TiO2/Si substrate was prepared by novel metallo-Organic process using spin coating technique. The structural and surface morphology were confirmed by X-Ray diffraction (XRD) atomic force microscope (AFM). Significantly improved ferroelectric properties (Ps ∼ 8.69, Pr ∼ 3.19 μC/cm2 and Ec ∼ 419kV/cm) and magnetic properties (Ms), (Mr) and (Hc) is (104emu/cc, 0.8emu/cc and 25Oe.) were observed at room temperature. Our observation provides an effective way to manipulate the conduction behavior to understand the leakage current density of multiferroic composites film at the interface. Poole-Frankel tunneling conduction mechanism dominates the leakage current of films in the relatively high electric filed. [ABSTRACT FROM AUTHOR]

In the present work, we have discussed the electrical transport properties of the polycrystalline NiCr2O4 by employing Impedance spectroscopy and DC resistivity techniques. It was observed that charge carriers follow Arrhenius type conduction throughout the temperature range. Activation energy (Ea) has been calculated from the impedance data, 0.462 for Rgb and 0.42 from Rg, which is well buttressed by the activation energy from the DC resistivity fitted data which is 0.468 eV. [ABSTRACT FROM AUTHOR]

BiMnO3 is a multiferroic material which means that it shows both the ferroelectricity and ferromagnetism. Present study deals about the study of optical and dielectric properties of BiMnO3 and doped BiMnO3. The magnetic and non magnetic ions are introduced as dopants in place of Mn sublattice, BiMn1-xAExO3 (where x=0.1 and AE= Cr, Fe, Co, and Zn). We have synthesized nanoparticles of BiMnO3 and BiMn1-xAExO3 (where x=0.1 and AE= Cr, Fe, Co, and Zn) by sol-gel technique. Optical properties have been studied by using FTIR (Fourier Transform Infrared) spectroscopy. FTIR (Fourier Transform Infrared Spectroscopy) analysis showed that there is an increase in the band gap of BiMn1-xAExO3 (where x=0.1 and AE= Cr, Fe, Co, and Zn) than pure BiMnO3 for the samples synthesized by sol-gel technique. The increase in band gap on doping is due to the radius to charge ratio. Ferroelectric hysteresis loop confirms the presence of ferroelectricity in BiMnO3. From the ferroelectric hysteresis loop the parameters like coericivity, saturation polarization and remanant polarization has been calculated. Nanoparticles of BiMnO3 have applications in memory storage devices. [ABSTRACT FROM AUTHOR]

Nano-crystalline BiFeO3 was synthesized by chemical combustion route. Magnetic study revealed a ferromagnetic behavior at room temperature with magnetic coercivity of ~ 808 Oe. First principles GGA + U investigations for bulk systems indicate that for collinear orientation of magnetic moments, there are intra-plane ferromagnetic and inter-plane anti-ferromagnetic coupling. However, after incorporation of spin-orbital (SO) coupling, the system stabilizes into a canted spiral spin structure. Maintaining resemblance with experimental scenario, we have investigated nano-clusters of the same material, which under collinear orientation, follow similar magnetic order as bulk. With SO-coupling and the consequential non-collinear canting of the surface Fe ions, experimentally observed magnetic behavior could be quantitatively reproduced along with additional prediction interesting attributes like half-metallic nature. [ABSTRACT FROM AUTHOR]

We report the modifications in the structural and dielectric properties of polycrystalline Bi1-xCaxFeO3 (BCFO) (x = 0.05, 0.10, 0.20) multiferroics understood in the context of grain and grain boundary contribution to the complex impedance and modulus behavior. It is seen that, in BCFO with increase in Ca-concentration, the insulating nature of both, grain and grain boundaries gets enhanced. Analysis of the Nyquist plots confirm the presence of non -Debye type relaxation in all the Ca-doped BCFO samples. [ABSTRACT FROM AUTHOR]

Four novel composite systems having composition "80 wt% BaFe12O19 (BaM)-20 wt% Na0.5Bi0.5TiO3 (NBT)" were prepared by solid state reaction technique with considering the variation of microstructure for both the phases. The formation of desired composite systems was confirmed by X-ray diffraction study. From SEM and FESEM images it was found that both the phases are well connected with each and forming 0-3 type particulate composite. From the magneto-capacitance data it was observed that, the composite system which have larger size (≈ micron range) matrix phase (BaM) and smaller size (≈ nano range) disperse phase has highest extrinsic magneto-capacitance (MC %) effect than others. In this report we were also tried to predict the intrinsic magneto-electric coupling in these four composite systems with the help of magneto-impedance spectroscopy. [ABSTRACT FROM AUTHOR]

Synthesis of Nd-doped BFO multiferroic nanoceramic by the conventional sol-gel method has been carried out. HRXRD and FESEM have been used for the structural analysis to confirm the triclinic structure and to obtain the surface morphology showing agglomeration and to find out the size of the nanoparticles. A high precision LCR meter has been used to record the dielectric constants at various temperatures. Several anomalies are observed whose physical explanations have been given. Space charge polarization effect and magnetoelectric coupling have been confirmed in the synthesized Bi0.9Nd0.1FeO3 nanoceramic sample. [ABSTRACT FROM AUTHOR]

Nano-crystalline BiFeO3 was synthesized by chemical combustion route. Magnetic study revealed a ferromagnetic behavior at room temperature with magnetic coercivity of ~ 808 Oe. First principles GGA + U investigations for bulk systems indicate that for collinear orientation of magnetic moments, there are intra-plane ferromagnetic and inter-plane anti-ferromagnetic coupling. However, after incorporation of spin-orbital (SO) coupling, the system stabilizes into a canted spiral spin structure. Maintaining resemblance with experimental scenario, we have investigated nano-clusters of the same material, which under collinear orientation, follow similar magnetic order as bulk. With SO-coupling and the consequential non-collinear canting of the surface Fe ions, experimentally observed magnetic behavior could be quantitatively reproduced along with additional prediction interesting attributes like half-metallic nature. [ABSTRACT FROM AUTHOR]

The Bi(1-x)PbxFeO3 (x=0, 0.1, 0.2, and 0.3) powders have been synthesized via a sol-gel method employing natural iron sands as Fe3+ ion source of starting material. Multiphase of bismuth ferrite such as BiFeO3, Bi25FeO40, and Bi2Fe4O9 were observed in the synthesized powders. The Pb doping decreases the phase formation of the BiFeO3 while increases the phases formation of other bismuth ferrite phases. A structural transformation from rhombohedral to pseudocubic system of the BiFeO3 was observed with the substitution of Pb2+. The powders exhibit BiFeO3 phase having crystal size of 27-83 nm. The Pb doping has strengthened both the magnetic and electric properties of the samples. The grain size of the powders decreased with the substitution of Pb-doping. The sample with x=0.1 shows the maximum magnetic moment at room temperature. The dielectric properties of the samples enhance with increasing Pb contents at room temperature. The magnetoresistance of the samples was estimated by the changes in the resistivity under the external magnetic field. [ABSTRACT FROM AUTHOR]

Lead free (Na0.5Bi0.5) 0.99La0.01Ti0.988 Fe0.012O3 (NBLTF) system has been synthesized by sol gel method without and with 2 mol% excess of Na and Bi. X-ray diffraction patterns of NBLTF samples confirm perovskite structure having rhombohedral R3c phase symmetry. Metal oxide band observed at ~ 629 cm-1 wavnumber in FTIR spectra also confirm formation of perovskite phase in samples. Microstructural analysis exhibits dense crystal growth having better grains connectivity for NBLTF sample with 2 mol% excess Na/Bi which is supported by room temperature DC resistivity measurements. Dense crystal growth and low leakage current with 2 mol% excess Na/Bi is reported to improve multiferroic properties of NBLTF sample and provides new insight to explore single phase lead free multiferroic system. [ABSTRACT FROM AUTHOR]

Polycrystalline ceramic samples of Zirconium (Zr)-doped GaFeO3 (GaFe1-xZrxO3) were studied using powder X-ray diffraction, complex impedance spectroscopy and Raman spectroscopic measurements to understand the effect of Zr doping on the structural and dielectric properties. The samples with varying Zr content were prepared by Sol-Gel method. X-ray data analysis confirmed the formation of single phase material without formation of any secondary phases and all are crystallized in Pc21n orthorhombic symmetry. Rietveld refinement of the X-ray data suggested an increase in the lattice constants due to size effect and decreases on x = 0.15 due to the effect of change in interplanner spacing. Impedance studies on the samples showed that the dielectric constant increases while loss tangent decrease as the Zr content increases. Raman scattering on GaFe1-xZrxO3 (x = 0, 0.05, 0.10, & 0.15) used to understand the composition dependence on phonon modes at room temperature. On Zr doping, Raman modes frequencies shifts to lower energies consistent with the X-ray data. [ABSTRACT FROM AUTHOR]

Polycrystalline Bi0.8Ba0.2FeO3 ceramic has been synthesized via conventional solid state reaction technique. The Rietveld refinement of x-ray powder diffraction revealed that the sample has a rhombohedral crystal structure (space group R3c). With increase in temperature, the values of dielectric constant (ε') and dielectric loss (tan d) are found to be increase at different frequencies which may be the result of increase in the number of charge carriers and their mobilities due to the thermal activation. Further the ac conductivity data is analyzed by using Jonscher's universal power law. The values of frequency exponent 's' lies in the range 0.2 ≤ s ≤ 0.7 and decreases with increase in temperature which can be explained on the basis of CBH (Correlated Barrier Height) model. [ABSTRACT FROM AUTHOR]

The multiferroic properties of BiFeO3 - CoFe2O4 (BFO-CFO) heterostructures thin film grown on (111) SrTiO3 (STO) substrates by employing pulsed laser deposition (PLD) method, have been studied.X ray diffraction analysis reveals the presence of BFO and CFO in two separate phases. The heterostructures BFO/CFO/STO(111) thin films show well - shaped hysteresis loop with saturated magnetization and coercive field, which are much larger than pure BFO/STO thin film. The frequency dependent dielectric anomalies in BFO-CFO multilayer are attributed to the interfacial effect across the presence of CFO as a separate phase embedded in BFO matrix. [ABSTRACT FROM AUTHOR]

Multiferroic 2-2 type bi-layered NFO/ (Pb0.80Sr0.20) TiO3 composite thin film on Pt/TiO2/Si substrate was prepared by novel metallo-Organic process using spin coating technique. The structural and surface morphology were confirmed by X-Ray diffraction (XRD) atomic force microscope (AFM). Significantly improved ferroelectric properties (Ps ~ 17.25, Pr ~8.02 µC/cm² and Ec ~ 404kV/cm) and magnetic properties (Ms ~ 117emu/cc, Mr ~ 0.83emu/cc and Hc ~ 20Oe) were observed at room temperature. The leakage current densities in NFO/PST composites film have been studied. Poole-Frankel bulk limited conduction mechanism dominates of film at relatively high electric filed. [ABSTRACT FROM AUTHOR]

Bi1-xPrxFe1-xTixO3 ceramics with x = 0.00, 0.10 and 0.20 were synthesized by solid state reaction method. Rietveld fitting of diffraction data reveals structural transition from rhombohedral phase (R3C) for x ≤ 0.10 to orthorhombic phase (Pnma) for x = 0.20. FTIR spectra exhibit broad absorption bands, which may be due to the overlapping of Fe-O and Bi-O vibrations in these ceramics. UV-visible spectroscopy results show strong absorption of light in the spectral range of 400-600 nm, indicating optical band gap in the visible region for these samples. [ABSTRACT FROM AUTHOR]

Polycrystalline Bi0.8Sm0.2FeO3 was synthesized by a simple co - precipitation route. Single phase of the prepared sample was confirmed by X-ray diffraction analysis which further reveals that it crystalizes as mixed crystal structure of rhombohedral with R3c space group and orthorhombic with Pnma space group. A considerable increase in magnetization was observed at room temperature VSM analysis and temperature dependent dielectric analysis shows an anomaly at the vicinity of Neel temperature (TN). Room temperature ferroelectric study explicitly authenticates the formation of a better loop due to the reduced leakage current and the suppression of oxygen deficiencies. [ABSTRACT FROM AUTHOR]

A pervoskite Bi0.5La0.5Fe0.5Cr0.5O3 (BLFC) nanoparticles were synthesized by high energy ball milling. Rietveld refined X-ray diffraction studies revealed that this compound shows orthorhombic structure with Pbnm space group. The dielectric studies were investigated in wide frequency (10²-106) range indicating giant dielectric permittivity behavior similar to LaFeO3 ceramic. The noted dielectric loss relaxation frequency dependent is as following the Arrhenius law can be ascribed as polaronic conduction. Further, magnetic transition at around 337 K and coexistence of weak ferromagnetic and antiferromagnetic behavior is observed below magnetic transition. [ABSTRACT FROM AUTHOR]

The multiferroic properties of BiFeO3 - CoFe2O4 (BFO-CFO) heterostructures thin film grown on (111) SrTiO3 (STO) substrates by employing pulsed laser deposition (PLD) method, have been studied.X ray diffraction analysis reveals the presence of BFO and CFO in two separate phases. The heterostructures BFO/CFO/STO(111) thin films show well - shaped hysteresis loop with saturated magnetization and coercive field, which are much larger than pure BFO/STO thin film. The frequency dependent dielectric anomalies in BFO-CFO multilayer are attributed to the interfacial effect across the presence of CFO as a separate phase embedded in BFO matrix. [ABSTRACT FROM AUTHOR]

Multiferroic ceramics are one of the most attractive materials for the next generation computer memories, smart sensors, and high frequency microelectronic devices. As compared to single phase multiferroic, piezoelectric-magnetostrictive composite materials exhibit larger magnetoelectric coefficients and therefore better suited for practical applications. In the present paper, we have provided a brief introduction on the multiferroic electro-ceramics followed by the outline of recent research trends on these materials. The potentials of flexible polymer-magnetostrictive composite materials, synthesized by economic chemical based processing routes, has been outlined. To make flexible multiferroic composites, cobalt iron oxide (CoFe2O4) (CFO) spinel powders were synthesized by a polymer assisted decomposition route. The cation mixing in as prepared as well as calcined CFO powders were investigated by XRD Rietveld refinement. Guided by the structural refinement results the processing conditions of the powder synthesis were optimized to yield spinal CFO powder with improved magnetic properties. These powders were dispersed into ferroelectric polyvinyledene (PVDF) matrix and the polymer-spinal composite was cast using different weight fractions of the spinel component. The composites were characterized in terms of its structure and microstructure. Preliminary dielectric and magnetic properties of these CFO-polymer composites is reported. [ABSTRACT FROM AUTHOR]

Single phase perovskite 0.9LaFeO3-0.1BaTiO3 ceramic was synthesized by the conventional solid-state reaction. Rietveld analysis of X-ray diffraction data clearly shows orthorhombic phase with Pbnm space group. The microstructure shows high density, uniform grains. The dielectric study shows the giant dielectric permittivity noted similar to that found in LaFeO3. The observed frequency dependent dielectric loss relaxation was ascribed as polaranic conduction. The present ceramic shows the enhanced magnetic properties and positive MD effect. The suitable explanation was given in present paper such for large dielectric permittivity and origin of positive MD effect in present ceramic. [ABSTRACT FROM AUTHOR]

A co-precipitation method has been adopted to synthesis Bi1-xGdxFeO3 (x = 0.00 and 0.15) nanoparticles. XRD studies confirms the phase formation and the crystallite size measured by using Debye-Scherrer relation reveals particle sizes of 72 and 36 nm for Bi1-xGdxFeO3 (x = 0.00) and Bi1-xGdxFeO3 (x=0.15) respectively. A distinct anomaly peak has been observed around 390°C in Bi1-xGdxFeO3 (x = 0.00) and 273°C in Bi1-xGdxFeO3 (x=0.15) from the temperature dependent dielectric studies attributed to the antiferromagnetic to paramagnetic phase transition. Bi1-xGdxFeO3 (x=0.15) shows better leakage current characteristics due to partial substitution of stable rare-earth Gd3+ ions for volatile Bi3+ ions leading to the reduction in oxygen vacancies. Further, Bi1-xGdxFeO3 (x = 0.00) shows lower remnant polarization value and a antiferromagnetic behavior. Whereas, Bi1-xGdxFeO3 (x=0.15) shows higher remnant polarization value and a weak ferromagnetic behavior. [ABSTRACT FROM AUTHOR]

Multiferroic BiFeO3 (BFO) nanoparticles (Nps) were synthesized using hydrothermal method. From the X-Ray diffraction analysis (XRD), the synthesized Nps were found to having rhombohedral structure with R3c space group confirmed by Rietveld analysis. Fourier transform infrared spectroscopy (FTIR) analysis was carried out to identify the chemical bonds present in the BFO Nps. Photocatalytic properties of synthesized Nps were studied for the degradation of Methylene Blue (MB) dye under visible light of 150W. [ABSTRACT FROM AUTHOR]

A new multiferroic Bi2FeMoO6 was synthesized by chemical route. The crystal structure was found to be distorted from cubic double perovskite structure, has rhombohedral symmetry. SEM reveals the formation of nanosized aggolomers and EDS confirms the material composition. Magnetic study shows the room temperature ferromagnetism. It also gives good co-existence of ferroelectricity at room temperature. These results suggests that the material can be envisaged as promising multiferroic material. [ABSTRACT FROM AUTHOR]

Nanostructured multiferroic Bi(1-x)BaxFeO3 x=0.0,0.1,0.2 were prepared by hydrothermal technique. The morphology of the particles changed with the doping of barium. Effect of barium doping on the dielectric constant was studied over a wide frequency range. The magnetization at the highest available field (~1.6T) increased from 0.05 emu/g for the sample with x=0.0 to 12 emu/g for the sample with x=0.2. Remnant polarization for x=0.0 was negligible and it increased to 0.06 μC/cm² for x=0.2. [ABSTRACT FROM AUTHOR]

Multiferroic Bi0.90La0.10Fe0.90Co0.10O3 ceramics have been synthesized via soft chemical co-precipitation method. From the X-ray diffraction analysis, ceramic powder sintered at 600°C was found to be single phase belonging to the rhombohedral structure with R3c space group confirmed by Rietveld analysis. Further, dielectric, Leakage and magnetic studies were performed at room temperature. [ABSTRACT FROM AUTHOR]

Single phase Bi1-xGdxFe1-yZryO3 (x=0.06;y=0, x= 0.10, y=0 and x=0.10,y= 0.03) nanoparticles were prepared to study the combined effect of Gd and Zr substitution on structural, magnetic and optical properties of BiFeO3. Rietveld refinement of X-ray diffraction patterns predicted that sample with x=0.06, y=0 was indexed to rhombohedral structure while samples with x=0.10, y=0 and x=0.10, y=0.03 were crystallized in multiphase (rhombohedral + orthorhombic). Magnetic properties were significantly enhanced with increasing concentration of Gd ions, however, magnetization reduced slightly with addition of 3% Zr ions in the system. Electron spin Resonance analysis indicated that breaking of spin cycloid is the main reason for enhancement of magnetization. Optical properties were investigated and direct band gap was found for all the samples. [ABSTRACT FROM AUTHOR]

Pure and co substituted Bi1-xYxFe1-xTixO3 (x = 0.24) ceramics were synthesized by solid state reaction method. X-ray diffraction patterns of Y and Ti codoped samples have shown single phase formation. Increasing Y and Ti concentration reveals structural transition from rhombohedral phase (R3c) for x = 0.16 to orthorhombic phase (Pnma) for x = 0.24. FT-IR spectra exhibit broad absorption bands, which may be due to the overlapping of Fe-O and Bi-O vibrations. UV-visible spectroscopy results show strong absorption of light in the spectral range of 400-720 nm, indicating optical band gap in the visible region for these samples. These interesting optical properties of co-substituted BFO samples in visible region may find potential applications in optoelectronic devices. [ABSTRACT FROM AUTHOR]

Single phase Bi1-xGdxFe1-yZryO3 (x=0.06;y=0, x= 0.10, y=0 and x=0.10,y= 0.03) nanoparticles were prepared to study the combined effect of Gd and Zr substitution on structural, magnetic and optical properties of BiFeO3. Rietveld refinement of X-ray diffraction patterns predicted that sample with x=0.06, y=0 was indexed to rhombohedral structure while samples with x=0.10, y=0 and x=0.10, y=0.03 were crystallized in multiphase (rhombohedral + orthorhombic). Magnetic properties were significantly enhanced with increasing concentration of Gd ions, however, magnetization reduced slightly with addition of 3% Zr ions in the system. Electron spin Resonance analysis indicated that breaking of spin cycloid is the main reason for enhancement of magnetization. Optical properties were investigated and direct band gap was found for all the samples. [ABSTRACT FROM AUTHOR]

Single phase polycrystalline samples of BixCo2-xMnO4 (x = 0.0, 0.1 and 0.3) were synthesized by conventional solid state reaction. The crystallographic structure of all samples is found to be cubic spinel (space group Fd3m). Partial substitution of Bi3+ in place of Co3+ varies the ferroelectric and ferrimagnetic transition temperatures. The magnetocapacitive effect exhibited in the temperature range 150–300 K suggests that the material can be envisaged as promising multiferroic. [ABSTRACT FROM AUTHOR]

Single phase polycrystalline samples of BixCo2-xMnO4 (x = 0.0, 0.1 and 0.3) were synthesized by conventional solid state reaction. The crystallographic structure of all samples is found to be cubic spinel (space group Fd3m). Partial substitution of Bi3+ in place of Co3+ varies the ferroelectric and ferrimagnetic transition temperatures. The magnetocapacitive effect exhibited in the temperature range 150–300 K suggests that the material can be envisaged as promising multiferroic. [ABSTRACT FROM AUTHOR]

We investigate here the temperature evolution of dc susceptibility and x-ray diffraction patterns of MnTi0.8Ru0.2O3. With increase in doping, a broad peak and a sharp peak is observed ~ 75 and 48 K, respectively in the dc susceptibility data. The broad peak corresponds to the 2 dimensional antiferromagnetic structure and the sharp peak to TN. The sharpness of TN suggests stronger 3 dimensional character. This is well depicted in the temperature dependent lattice parameters also. These results provide playground for understanding the role of Ti ions, dimensional cross over on the exotic properties exhibited by them. [ABSTRACT FROM AUTHOR]

We investigate here the temperature evolution of dc susceptibility and x-ray diffraction patterns of MnTi0.8Ru0.2O3. With increase in doping, a broad peak and a sharp peak is observed ~ 75 and 48 K, respectively in the dc susceptibility data. The broad peak corresponds to the 2 dimensional antiferromagnetic structure and the sharp peak to TN. The sharpness of TN suggests stronger 3 dimensional character. This is well depicted in the temperature dependent lattice parameters also. These results provide playground for understanding the role of Ti ions, dimensional cross over on the exotic properties exhibited by them. [ABSTRACT FROM AUTHOR]

Pure and Mn doped KNbO3 have been prepared by ball milling assisted ceramic method. Mn ion had been doped at Nb site to induce ferromagnetism at room temperature. X-ray diffraction (XRD) patterns reveal the formation of orthorhombic phase. High resolution scanning electron micrograph (HR-SEM) of both pure and Mn doped samples show a mixture of spherical and plate like particles. Room temperature magnetic behavior of both the samples were analyzed using vibrating sample magnetometer (VSM). 5% Mn doped KNbO3 exhibits ferromagnetic behavior. Observed ferromagnetic feature has been explained by interactions between bound magnetic polarons which are created by Mn4+ ions. [ABSTRACT FROM AUTHOR]

Pure and Mn doped KNbO3 have been prepared by ball milling assisted ceramic method. Mn ion had been doped at Nb site to induce ferromagnetism at room temperature. X-ray diffraction (XRD) patterns reveal the formation of orthorhombic phase. High resolution scanning electron micrograph (HR-SEM) of both pure and Mn doped samples show a mixture of spherical and plate like particles. Room temperature magnetic behavior of both the samples were analyzed using vibrating sample magnetometer (VSM). 5% Mn doped KNbO3 exhibits ferromagnetic behavior. Observed ferromagnetic feature has been explained by interactions between bound magnetic polarons which are created by Mn4+ ions. [ABSTRACT FROM AUTHOR]

High quality polycrystalline YCrO3 samples were synthesized using solid-state-reaction method. The samples were subsequently characterized using X-ray diffraction and magnetometry. Further, temperature dependent Raman spectroscopy over a spectral range from 100 to 800 cm-1 was used to examine the variation of phonons as a function of temperature from 90 to 300 K. In the low temperature ferroelectric phase of YCrO3, the observed phonon spectra showed softening of some Raman modes below the magnetic ordering temperature (TN ~ 142K), suggesting a coupling between the spin and phonon degrees of freedom. [ABSTRACT FROM AUTHOR]

Our high pressure x-ray diffraction studies on BiMn1.5Ti0.5O5 show iso-structural phase transition above 12 GPa similar to the one observed in undoped BiMn2O5; however anisotropic compressional behavior is found to be more enhanced in the doped case. Unlike undoped system, an anomalous lattice expansion along c axis has been observed in BiMn1.5Ti0.5O5 above 12 GPa; whereas the b lattice parameter has been found to be more compressible as compared to BiMn2O5. As doping with Ti reduces the magnetic interactions among Mn ions, the observed changes are suggestive of having adverse magnetic implications in the observed iso-structural phase transition. [ABSTRACT FROM AUTHOR]

High quality polycrystalline YCrO3 samples were synthesized using solid-state-reaction method. The samples were subsequently characterized using X-ray diffraction and magnetometry. Further, temperature dependent Raman spectroscopy over a spectral range from 100 to 800 cm-1 was used to examine the variation of phonons as a function of temperature from 90 to 300 K. In the low temperature ferroelectric phase of YCrO3, the observed phonon spectra showed softening of some Raman modes below the magnetic ordering temperature (TN ~ 142K), suggesting a coupling between the spin and phonon degrees of freedom. [ABSTRACT FROM AUTHOR]

Our high pressure x-ray diffraction studies on BiMn1.5Ti0.5O5 show iso-structural phase transition above 12 GPa similar to the one observed in undoped BiMn2O5; however anisotropic compressional behavior is found to be more enhanced in the doped case. Unlike undoped system, an anomalous lattice expansion along c axis has been observed in BiMn1.5Ti0.5O5 above 12 GPa; whereas the b lattice parameter has been found to be more compressible as compared to BiMn2O5. As doping with Ti reduces the magnetic interactions among Mn ions, the observed changes are suggestive of having adverse magnetic implications in the observed iso-structural phase transition. [ABSTRACT FROM AUTHOR]