arXiv subjects

B. Santhosh Kumar

Publications and source records attributed to B. Santhosh Kumar.

3 recordsLinked to original sources

arXiv2020

Concurrence of ferroelectric, dielectric and magnetic behaviour in Tb2Ti2O7 pyrochlore

We report the ferroelectric property in Tb2Ti2O7 pyrochlore, prepared by a two-step solid-state reaction method. A concave P-E (polarisation vs electric field) loop observed from 382 K confirms ferroelectricity, below which the loop remains as pointed or banana-shaped. Dielectric plots clearly show an anomaly at 383 K and the magnetic data reveals a deviation from 380 K supporting the observed ferroelectric ordering. The origin of ferroelectricity in Tb2Ti2O7 is discussed which is due to the structural distortion in TiO6 octahedron.

cond-mat.mtrl-sci↗

arXiv2020

First Observed Metal-like to Insulator Transition in the vacant 3d orbital Quantum Spin Liquid Tb$_2$Ti$_2$O$_7$

We report the observation of metal-like to insulator transition (MTI) in the 3dpyrochlore oxide Tb2Ti2O7 at 603 K due to the interaction of empty 3d orbitals of Ti4+ with O2- ions, evidenced by the transition in resistivity. Magnetisation, specific heat capacity and differential scanning calorimetry support the MTI, and the transition is of second order. An appreciable change in magnetisation with temperature, without any magnetic phase transition, is a behaviour typical in this family of compounds which is seldom observed in empty d orbital pyrochlores. The possible mechanism that supports the MTI in Tb2Ti2O7 is discussed. Subsequently, a broad change in magnetisation from 696 K is also seen. Thermogravimetric analysis confirms the observed MTI (603 K) and the broad change in magnetisation (696 K)are not due to oxygen vacancy

cond-mat.mtrl-sci↗

arXiv2018

Magneto-dielectric and Magneto-resistive in the Mixed Spinel MgFe2O4

The mixed spinel, MgFe2O4 has been synthesized by ball-milling assisted sintering method. X-ray diffraction study confirms formation of cubic MgFe2O4 and the lattice parameter values calculated are a = b = c = 8.369(3) Å. Vibrating sample magnetometer measurements at room temperature shows a soft ferrimagnetic nature. Magneto-Dielectric and Magneto-Restive plots confirm coupling at room temperature in the prepared MgFe2O4. The peak at 500 Oe in the MD plot is due to the canting of Fe3+ ions distributed in octahedral and tetrahedral sites.

cond-mat.mtrl-sci↗