Multiferroic composite ferroelectric-ferromagnetic films

Abstract

Multiferroic behavior was confirmed for epitaxial composite ferroelectric-ferromagnetic heterostructures, using a ferromagnetic crystal as both substrate and straining medium. Heterostructures having 2-2 connectivity (plane-on-plane) were fabricated by chemical solution deposition of Pb(Zr0.3,Ti0.7)O3 (PZT) thin films on La1.2Sr1.8Mn2O7 (LSMO) single crystal substrates. Magnetostriction (0.13%) of the substrate at its transition temperature (∼105K) induces an abrupt 7.3% increase in switchable polarization of the PZT. This confirmation of elastic coupling induced by the onset of ferromagnetism is a first step toward fabricating such structures for study of the interrelationship of their magnetic and electrical field-dependent behaviors.