Research Projects

Spin-orbit materials are crucial for spintronics applications as they enable charge-spin current interconversion. Spin current generation from a charge current, which exerts a spin-orbit torque (SOT) upon interaction with a ferromagnet, is of interest. Over the past decade, various materials have been studied to understand the microscopic origin of charge-spin current conversion and SOT. However, recent focus has shifted towards improving the efficiency of charge-spin current conversion and SOT. Oxidation of the metallic layer can significantly enhance conversion and SOT efficiency in ferromagnet/metal heterostructures. Researchers have discovered robust spin current generation in heterostructures containing insulating Aurivillius phase oxide Bi₂WO₆ and ferromagnetic Ni₀.₈Fe₀.₂ layers, where the SOT efficiency rivals that of contemporary spin-orbit materials. The interface and accompanying Rashba Edelstein effect are expected to play a dominant role in improving efficiency. To develop a deeper understanding of the underlying mechanism and potentially establish a novel class of spin-orbit materials with giant charge-spin conversion and SOT efficiencies, a systematic study of Aurivillius phase oxides is proposed. The Aurivillius oxides contain transition metal atoms spanning the periodic table's 3d to 5d block, allowing them to be used as a testbed to tune spin-orbit coupling strength, orbital hybridization, and built-in electric field.