Prof Dr S.Panigrahi completed his Ph.D from Berhampur University, Odisha India. Presently he is senior professor In National Institute of Technology (NIT) Rourkela India. He has published more than 200 papers in journals of repute and members of different editorial boards
-Multiferroicity is a property of a material which arises when two or more ferroic orders coexist in a single phase of a material. It has attracted renewedinterest during the past decade.Especially, multiferroicswith magnetic and ferroelectric (FE) orders have been underintense investigation, both experimentally and theoretically, due to their possible applications for memory devices. The compound NdCrTiO5 (NCTO) is a well known type II multiferroic with spontaneous electric polarisation associated with its magnetic transition at TN=21K.In this work, the structural, dielectric and impedance spectroscopic studies of polycrystalline NdCrTiO5 have been investigated. The rietveld refinement of XRD shows that prepared ceramics crystallized in single phase at room temperature (RT) with orthorhombic symmetry in space group Pbam. Thethermal variation of the real (εr') and imaginary (εr") part of the complex dielectric constant exhibited the increasing values above 450K, indicating an enhanced conductivity at elevated temperatures in the prepared specimen. The impedance spectroscopic studies revealed the systematic occurrence of the both grain and grain boundary conduction and relaxations.
Prof. D. Behera has completed his Ph.D. from Utkal University, Bhubaneswar, India. He is the Head of the Department of Physics and Astronomy, NIT Rourkela, a premier Engineering Institute of India. He has published more than 75 papers in reputed journals and has been serving as Professor in Physics.
Ilmenite/spinel NiMnO3/NiMn2O4 nanocotton and multiwall carbon nanotube (MWCNT) blended composites were prepared via one step sol-gel auto combustion route and ultra-sonication techniques with a view to investigate its conduction response with temperature and improved supercapacitor performance. The X-ray diffractometry, FTIR and Raman techniques were utilized to ascertain its phase formation and structural information. The growth of nanoparticles homogeneously and cotton-like morphology were collected from FESEM and TEM micrographs with true stochiometrical ratios of elemental particles Ni, Mn, O and C. The coercivity (264 Oe) and saturation magnetization (1.2 emu/gm.) of MWCNT blended NiMnO3/NiMn2O4 decreases significantly. The fitted Nyquist plot ( ) distinguishes the indivisual contribution of grain and grain boundary. Activation energy for grain (0.87 eV) and grain boundary (1.2 eV) was calculated from liner plot of extracted parameter. The variation of conductivity spectra with frequency was fitted with a modified equation of Jonscher's Power Law proposed by us, . The temperature dependent frequency exponent (n) and Ln (A) suggests non-overlapping small polaron tunneling model for its conduction mechanism. The damping coefficient and peak frequency from fitted imaginary dielectric spectra suggested relaxation type dielectric response in NiMnO3/NiMn2O4 nanosystem. The electrochemical properties of NiMnO3/NiMn2O4 and MWCNT blended NiMnO3/NiMn2O4 were examined in 2 M aqueous KOH solution and excellent capacitive properties were observed for both compounds. Higher capacitance value (1347 F-g-1) and energy density 140 W h kg−1 was obtained at current density of 5 A g−1 for MWCNT blended composition with compared to its parent counterparts to act as a better supercapacitor.