Voltage-controlled magnetic device operating over a wide temperature range

摘要

A voltage-controlled spintronic device includes a magnetic layer having an effective anisotropy Keff; a non-magnetic insulating layer; a contact layer; the magnetic layer having an anisotropy switching threshold such that application of a polarization voltage Vmax allows switching of the effective anisotropy Keff from a direction perpendicular to the reference plane to a direction in the reference plane or vice versa, the magnetic layer including a first layer, with thickness tB, having a volume anisotropy KVB; a second layer, with thickness tA, having a surface anisotropy KSA and a volume anisotropy KVA; the surface anisotropy KSA and the volume anisotropies KVA and KVB respecting, over a given operating temperature range: Min(KSA(V=0), KSA(V=Vmax))<−{KVBtB+KVAtA)

主权项

1. A voltage-controlled magnetic device comprising:
a magnetic layer extending along a reference plane and having a variable direction magnetisation and an effective anisotropy Keff; a non-magnetic insulating layer extending onto the magnetic layer; a contact layer extending onto the non-magnetic insulating layer; a polarisation voltage device configured to apply a polarisation voltage between the contact layer and the magnetic layer, through the non-magnetic insulating layer; said magnetic layer having an anisotropy switching threshold such that the application of a polarisation voltage Vmax through the non-magnetic insulating layer enables switching of the effective anisotropy Kerr from a direction perpendicular to the reference plane to a direction in the reference plane or vice versa, wherein the magnetic layer comprises: a first layer with thickness tB, having a first volume anisotropy KVB; a second layer with thickness tA, having a surface anisotropy KSA and a second volume anisotropy KVA, the second layer being situated between the first layer and the non-magnetic insulating layer; a composition and a thickness of the second and first layers being chosen in order that the surface anisotropy KSA and the first and second volume anisotropies KVB and KVA respect, over a given operating temperature range, the following inequality:
Min=(KSA(V=0),KSA(V=Vmax))<−KVBtB+KVAtA)