Large voltage-induced magnetic anisotropy field change in ferrimagnetic FeGd

The voltage-induced magnetic anisotropy change of an ultrathin ferrimagnetic FeGd alloy has been characterized using V vertical bar Fe90Gd10 vertical bar MgO vertical bar Fe magnetic tunnel junctions. The bias-voltage dependence of the magnetoresistance measurement reveals the voltage-induced anisotropy change in the V vertical bar Fe90Gd10 vertical bar MgO junction. The magnetic anisotropy field change (Delta H-k) in Fe90Gd10 is about twice that in Fe owing to the small net magnetization of the former. Therefore, employing ferrimagnetic materials is a promising option for voltage-controlled frequency-tunable spintronic devices. (C) 2015 The Japan Society of Applied Physics