Magnetoelectric behaviour of ferrimagnetic BixCo2-xMnO4 (x=0, 0.1 and 0.3) thin films

Abstract

Thin films of BixCo2-xMnO4 (x=0, 0.1 and 0.3) were grown on quartz, LaAlO3 (LAO) and YBa2Cu3O7 (YBCO) buffer layer coated-LAO substrates by pulsed laser deposition (PLD). X-ray diffraction (XRD) and Raman scattering measurements showed that the thin films exhibit single phase polycrystalline cubic spinel structure on all the substrates. Near edge x-ray absorption fine structure (NEXAFS) studies confirmed the octahedral occupancy of the substituted Bi3+ ions. Temperature dependent zero field cooled (ZFC) magnetization measurements show the ferrimagnetic (FM) behavior (TC186 K) and magnetization undergoes a cross-over from positive to negative, owing to the opposite contributions of magnetic moments from Co and Mn ions. A weak ferroelectric property exhibited by the films above room temperature was evidenced through the Capacitance-Voltage (C-V) and dielectric measurements. Magnetoelectric coupling was found maximum just below the FM-TC.