Electric field control of magnetism in complex oxide heterostructures

Full text: Considerable interest has been devoted recently to designing systems where magnetic and ferroelectric orders coexist (multiferroics), and where the presence of a magnetoelectric coupling could enable the electrostatic control of magnetism in the solid state. By exploring interfacial couplings between magnetic and ferroelectric phases of composite systems, magnetoelectric couplings larger than those typical of single-phase multiferroics have been achieved. In this contribution, I'll present our recent experimental results demonstrating a large magnetoelectric coupling in PZT/LaSrMnO3 multiferroic heterostructures, manifest in the modification of the magnetic properties of LaSrMnO3 with the PZT ferrolectric polarisation state. The effect is electronic in origin, as shown by x-ray near edge absorption spectroscopy. From the measured change in magnetic moment and Mn valency, we conclude that the interfacial spin ordering is modified upon charge doping. This ability to control spin via electric fields opens a new pathway for the development of novel spin-based technologies. (author)