Thermally stable perpendicular magnetic anisotropy features of [Co/Pd](m) multilayer matrix integrated with [CoO/Pd](n) bottom layer

Abstract

We evaluated the perpendicular magnetic anisotropy (PMA) features of a hybrid [CoO/Pd](2)/[Co/Pd](7) multilayer (ML) matrix under annealing in which the [CoO/Pd](2) bottom layer was inserted. Annealing allowed for the diffusion of oxygen atoms existing in the inserted [CoO/Pd](2) layer, leading to an atomic structural reconfiguration event. The hybrid matrix was crucial to result in a higher effective anisotropy energy (3.40 Merg/cc) than an ordinary [Co/Pd](7) ML matrix (1.25 Merg/cc) under annealing at 450 degrees C. X-ray photoelectron spectroscopy confirmed the presence of Co-O bonding states and annealing dependent oxygen atom diffusion. The possible nature of the enhanced PMA features is discussed.