Metastable permalloy monoxide based spin valves and pseudo-spin valves

Abstract

We report the reactive magnetron sputter deposition of a metastable antiferromagnetic oxide, (Ni81Fe19)O or permalloy monoxide (PyO), suitable for exchange biasing permalloy (Ni81Fe19 or Py) film layers at room temperature or for manipulating metallic Py film coercivities. Examples are presented demonstrating how PyO can be incorporated in Py/Cu/Py-based exchange biased spin valves (SV) or nonexchange biased pseudo-spin valves (PSV) using the same metallic Py target for fabricating both the PyO pinning layer and the Py metallic layers. The presence of a Ti seed layer beneath the PSV or SV film structures and the oxidized silicon substrate is shown to have an insignificant effect on the film magnetic properties, demonstrating the feasible use of Ti as an adhesion or diffusion barrier layer in hybridized microelectronic devices based on silicon. Glancing incidence parallel beam x-ray diffraction data are presented supporting the existence of the antiferromagnetic monoxide rocksalt phase for the PyO. In addition, vibrating sample magnetometry and four point probe magnetoresistance analysis data are presented for the SV and PSV films.