Giant Extrinsic Spin Hall Effect in Platinum‐Titanium Oxide Nanocomposite Films

Abstract

Abstract Although the spin Hall effect provides a pathway for efficient and fast current‐induced manipulation of magnetization, application of spin–orbit torque magnetic random access memory with low power dissipation is still limited to spin Hall materials with low spin Hall angles or very high resistivities. This work reports a group of spin Hall materials, Pt1−x(TiO2)x nanocomposites, that combines a giant spin Hall effect with a low resistivity. The spin Hall angle of Pt1−x(TiO2)x in an yttrium iron garnet/Pt1−x(TiO2)x double‐layer heterostructure is estimated from a combination of ferromagnetic resonance, spin pumping, and inverse spin Hall experiments. A giant spin Hall angle 1.607 ± 0.04 is obtained in a Pt0.94(TiO2)0.06 nanocomposite film, which is an increase by an order of magnitude compared with 0.051 ± 0.002 in pure Pt thin film under the same conditions. The great enhancement of spin Hall angle is attributed to strong side‐jump induced by TiO2 impurities. These findings provide a new nanocomposite spin Hall material combining a giant spin Hall angle, low resistivity and excellent process compatibility with semiconductors for developing highly efficiency current‐induced magnetization switching memory devices and logic devices.

Keywords

• ferromagnetic resonance
• memory devices
• nanocomposite films
• spin Hall effect
• spin pumping