Ultrahigh Anomalous Hall Sensitivity in Co/Pt Multilayers by Interfacial Modification

Abstract

A large enhancement of anomalous Hall sensitivity (Sv) by metal/oxide interfacial modification is obtained in a MgO/[Co/Pt]3/MgO multilayered structure. The values of Sv are increased to 8363 V/A·T by CoO insertion and 2261 V/A·T by Pt insertion, while Sv is approximately 1000 V/A·T in normal Hall semiconductor sensors. Microstructural analysis shows that the crystal orientation of [Co/Pt]3 multilayers is improved, and the oxygen concentration is largely changed by introducing an ultrathin CoO layer at metal/oxide interfaces, leading to a large increment of Sv. © 2013 The Japan Society of Applied Physics.