US Patent 10586579 Electric field switchable magnetic devices

A magnetic device may include a layer stack. The layer stack may include a first ferromagnetic layer; a non-magnetic spacer layer on the first ferromagnetic layer, where the non-magnetic spacer layer comprises at least one of Ru, Ir, Ta, Cr, W, Mo, Re, Hf, Zr, or V; a second ferromagnetic layer on the non-magnetic spacer layer; and an oxide layer on the second ferromagnetic layer. The magnetic device also may include a voltage source configured to apply a bias voltage across the layer stack to cause switching of a magnetic orientation of the second ferromagnetic layer without application of an external magnetic field or a current. A thickness and composition of the non-magnetic spacer layer may be selected to enable a switching direction of the magnetic orientation of the second ferromagnetic layer to be controlled by a sign of the bias voltage.