Temperature Variation of Magnetic Anisotropy inPt/Co/AlOxTrilayers

Perpendicular magnetic anisotropy at metal/oxide interfaces continues to receive great interest, from the viewpoints of both fundamental research and spintronic applications. In a detailed investigation of the magnetic properties of Pt/Co/AlO${}_{x}$ sandwiches, unusual phenomena are observed, including reorientation of anisotropy as a function of temperature, and the onset of exchange bias associated with very large coercivity and anisotropy field at low temperature. These are interpreted in terms of chemical bonding and varying material phases in the trilayers.