Magnetoelectric coupling and AC electrical properties of xLa0.7Sr0.3MnO3 – (1-x) HoMnO3 (x = 0.1, 0.3 and 0.5) lead free multiferroic nanocomposites

Abstract

We have investigated magnetoelectric effect and ac electrical properties of xLa0.7Sr0.3MnO3 (LSMO) - (1-x) HoMnO3 (HMO) (x = 0.1, 0.3 and 0.5) multiferroic nanocomposites prepared through low temperature pyrophoric reaction method. The series of nanocomposites have been found to exhibit room temperature ferroelectric and ferromagnetic behaviour. The magnetoelectric response has been detected in this series of lead free nanocomposites at room temperature. The ac electrical properties of this series of composite have been studied employing impedance spectroscopy technique. The value of impedance has been found to be decreased with increase in magnetic field. This observation has been attributed to the depinning of LSMO domain walls at the grain boundaries pinning centres and thereby enhancing the spin dependent transport mechanism in the composites. Moreover, impedance has been observed to decrease with increase in both frequency and temperature due to the charge carrier or polarons of the system acquiring sufficient amount of thermal energy to overcome the high resistive barrier. Nyquist plots at different temperatures have been fitted using parallel combinations of grain boundaries resistance and grain boundaries capacitance for LSMO and HMO grains, where grain boundaries resistances are found to decrease with increase in temperatures. Furthermore, we have estimated activation energy of those composites at a same temperature range using Arrhenius relation.