Magnetocapacitance effect in perovskite-superlattice based multiferroics

Abstract

We report the structural and magnetoelectrical properties of La0.7Ca0.3MnO3∕BaTiO3 perovskite superlattices grown on (001)-oriented SrTiO3 by the pulsed laser deposition technique. Magnetic hysteresis loops, together with temperature dependent magnetic properties, exhibit well-defined coercivity and magnetic transition temperature (TC) ∼140K. dc electrical studies of films show that the magnetoresistance (MR) is dependent on the BaTiO3 thickness, and negative MR as high as 30% at 100K are observed. The ac electrical studies reveal that the impedance and capacitance in these films vary with the applied magnetic field due to the magnetoelectrical coupling in these structures—a key feature of multiferroics. A negative magnetocapacitance value in the film as high as 3%pertesla at 1kHz and 100K is demonstrated, opening the route for designing novel functional materials.