Magnetoelectric effects arise when magnetic and electrical signals are interconverted using materials, with possible applications that include low-power data storage and magnetic-field sensing. We primarily study ferromagnetic films that experience voltage-driven strain from ferroelectric underlayers. The resulting magnetic changes are imaged using magnetic force microscopy (MFM) and photoemission electron microscopy (PEEM). This latter technique relies on x-ray magnetic circular dichroism (XMCD) to achieve magnetic contrast.
The image to the right shows magnetic domains in a manganite film whose magnetization is inhomogeneous in magnitude. Field of view has diameter 6 micrometres. [After Nature Materials 12 (2013) 52-58].
The ability to send spin-polarized electrons through a non-magnetic channel running between ferromagnetic electrodes could be exploited in future logic and memory devices with low power consumption. Having previously shown that a carbon nanotube can carrry spin-polarized electrons without significant depolarization, attention is currently focussed on its well known allotrope graphene.
Image to the left shows carbon nanotube (CNT) between manganite electrodes of LSMO [A. Fert, Angew. Chem. Int. Ed. 47 (2008) 5956].