Dr Suchismita Samantray - Academia.edu (original) (raw)
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National Institute of Technology, Calicut
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Papers by Dr Suchismita Samantray
Advanced Science Letters, 2014
ABSTRACT This paper reports oxygen vacancy mediated defect mechanism responsible for exhibiting u... more ABSTRACT This paper reports oxygen vacancy mediated defect mechanism responsible for exhibiting unusually high dielectric constant anomaly observed around room temperature in polycrystalline GdMnO3 (GMO). Bulk ceramics of GMO are prepared by solid state reaction technique using slow step sintering schedule. The compound sintered at 1350 °C showed sharp and unusually high dielectric constant (∼140,000) at 373 K in 10 KHz frequency. Details studies of XPS spectra are carried out and analysed to understand the contribution of defect process caused by the oxygen vacancies during high temperature sintering of pure GMO bulk ceramics. It is observed from O 1S spectra that the middle binding energy peak noted at 531.25 eV represents the defect peak/oxygen deficient region associated with the GMO system. An attempt is more to correlate the defect process observed from XPS studies with the abnormal increase of high dielectric constant anomaly reported in the our earlier paper.
Journal of Physics and Chemistry of Solids, 2010
Journal of Materials Science: Materials in Electronics, 2013
ABSTRACT This paper reports the dielectric and magnetic properties of DyMnO3 (DMO) ceramics sinte... more ABSTRACT This paper reports the dielectric and magnetic properties of DyMnO3 (DMO) ceramics sintered at 1,100 and 1,350 °C temperature for 10 h. Sample sintered at 1,100 °C showed presence of secondary phases of Dy2O3 whereas the monophasic orthorhombic structure of DyMnO3 sample is synthesized only at sintering temperature of 1,350 °C. The dielectric properties of the sintered sample of DMO were investigated as a function of temperature (T ≥ 300 K) and frequency (10 kHz–1 MHz). Both the sintered samples showed frequency independent dielectric anomaly at 313 K. These samples exhibited ferroelectric behavior at room temperature which was evidenced from the polarization hysteresis loop measurement. No magnetic transition has been observed at room temperature. However, magnetic field dependent magnetization and temperature dependent magnetization showed the paramagnetic behavior of the DyMnO3 samples.
Journal of Magnetism and Magnetic Materials, 2013
Journal of Alloys and Compounds, 2011
Journal of Magnetism and Magnetic Materials, 2013
ABSTRACT The effect of sintering temperature on structural, electrical and magnetic behaviours of... more ABSTRACT The effect of sintering temperature on structural, electrical and magnetic behaviours of polycrystalline samples of Ho0.9Ca0.1Mn0.9Co0.1O3 prepared by the solid state reaction route sintered at three different temperature 1250 °C, 1350 °C, 1450 °C for 10 h are investigated. XRD, SEM, magnetization, dielectric and ferroelectric measurements were carried out. Experimental results showed the nucleation of orthorhombic phase as the sintering temperature increases from 1250 °C to 1450 °C. Ferroelectric (Tc) and antiferromagnetic transition temperature (TN) increases with increase in sintering temperature. Strong bifurcation of FC and ZFC curve in sample sintered at 1450 °C showed a clear onset of ferromagnetic state around 165 °K, which is confirmed from M to H graph at 165 °K. All the sample showed ferroelectric behaviour at room temperature which are leaky in nature. Sintering temperature along with Ca and Co doping in HoMnO3 ceramics plays an important role in phase transformation along with enhancement in multiferroic properties.
Advanced Science Letters, 2014
ABSTRACT This paper reports oxygen vacancy mediated defect mechanism responsible for exhibiting u... more ABSTRACT This paper reports oxygen vacancy mediated defect mechanism responsible for exhibiting unusually high dielectric constant anomaly observed around room temperature in polycrystalline GdMnO3 (GMO). Bulk ceramics of GMO are prepared by solid state reaction technique using slow step sintering schedule. The compound sintered at 1350 °C showed sharp and unusually high dielectric constant (∼140,000) at 373 K in 10 KHz frequency. Details studies of XPS spectra are carried out and analysed to understand the contribution of defect process caused by the oxygen vacancies during high temperature sintering of pure GMO bulk ceramics. It is observed from O 1S spectra that the middle binding energy peak noted at 531.25 eV represents the defect peak/oxygen deficient region associated with the GMO system. An attempt is more to correlate the defect process observed from XPS studies with the abnormal increase of high dielectric constant anomaly reported in the our earlier paper.
Journal of Physics and Chemistry of Solids, 2010
Journal of Materials Science: Materials in Electronics, 2013
ABSTRACT This paper reports the dielectric and magnetic properties of DyMnO3 (DMO) ceramics sinte... more ABSTRACT This paper reports the dielectric and magnetic properties of DyMnO3 (DMO) ceramics sintered at 1,100 and 1,350 °C temperature for 10 h. Sample sintered at 1,100 °C showed presence of secondary phases of Dy2O3 whereas the monophasic orthorhombic structure of DyMnO3 sample is synthesized only at sintering temperature of 1,350 °C. The dielectric properties of the sintered sample of DMO were investigated as a function of temperature (T ≥ 300 K) and frequency (10 kHz–1 MHz). Both the sintered samples showed frequency independent dielectric anomaly at 313 K. These samples exhibited ferroelectric behavior at room temperature which was evidenced from the polarization hysteresis loop measurement. No magnetic transition has been observed at room temperature. However, magnetic field dependent magnetization and temperature dependent magnetization showed the paramagnetic behavior of the DyMnO3 samples.
Journal of Magnetism and Magnetic Materials, 2013
Journal of Alloys and Compounds, 2011
Journal of Magnetism and Magnetic Materials, 2013
ABSTRACT The effect of sintering temperature on structural, electrical and magnetic behaviours of... more ABSTRACT The effect of sintering temperature on structural, electrical and magnetic behaviours of polycrystalline samples of Ho0.9Ca0.1Mn0.9Co0.1O3 prepared by the solid state reaction route sintered at three different temperature 1250 °C, 1350 °C, 1450 °C for 10 h are investigated. XRD, SEM, magnetization, dielectric and ferroelectric measurements were carried out. Experimental results showed the nucleation of orthorhombic phase as the sintering temperature increases from 1250 °C to 1450 °C. Ferroelectric (Tc) and antiferromagnetic transition temperature (TN) increases with increase in sintering temperature. Strong bifurcation of FC and ZFC curve in sample sintered at 1450 °C showed a clear onset of ferromagnetic state around 165 °K, which is confirmed from M to H graph at 165 °K. All the sample showed ferroelectric behaviour at room temperature which are leaky in nature. Sintering temperature along with Ca and Co doping in HoMnO3 ceramics plays an important role in phase transformation along with enhancement in multiferroic properties.