Perpendicular Magnetic Anisotropy of Amorphous Ferromagnetic CoSiB/[Pt,Au] Multilayer

Abstract

Perpendicular magnetic anisotropy is being widely studied as a possible candidate for a high-density spin-transfer torque magnetic random access memory. The key issues of a high-density spin-transfer torque magnetic random access memory are decreasing the switching current and the high thermal stability. In order to solve these problems, two approaches are suggested: One is the development a new amorphous ferromagnetic material as a pinned layer for a multilayer with a low saturated magnetization (M-s) value because of the interface roughness between the two layers. The other is a search for the most suitable materials with high perpendicular magnetic anisotropy in order to have high thermal stability. In this work, we present an amorphous ferromagnetic Co75Si15B10 material and compare the magnetic properties of a [CoSiB (0.3, 0.4, 0.5 nm)/Pt (1.4 nm)](5) multilayer and new combinations [CoSiB (0.3, 0.4, 0.5 nm)/Au (1.5 nm)](5).