Approaches towards ferroelectric control of thin film magnetism

Abstract

We discuss three different approaches towards ferroelectric control of thin film magnetism and recent experimental results. Firstly, ferromagnetic films of doped LaMnO3 were grown on piezoelectric Pb(Mg1/3Nb2/3)0.72Ti0.28O3(001) crystals and have been strained reversibly by up to 0.15%. The strain modulation is accompanied by large magnetization changes (for example, of 25% at ambient temperature in La0.7Sr0.3MnO3), strong resistance modulations and a shift of the magnetic Curie temperature. Secondly, the concept of a multiferroic field-effect transistor comprising a magnetic channel and a ferroelectric gate is introduced. We discuss the effect of piezoelectric gate strain. Finally, the first results on single-phase multiferroic films of HoMnO3 are described. Epitaxial films have been prepared by the pulsed laser deposition technique.