Spin Relaxation and Size Effects in Cu and Al Nanowires

Abstract

This dissertation focuses on the quantification of dominant spin relaxation sources in Cu and Al. In light metals, the Elliott-Yafet (EY) theory is widely acknowledged to describe the proportionality between the spin relaxation rate and the momentum scattering rate for a single scattering source. However, the quantitative impact on spin relaxation due to the presence of multiple scattering sources has remained poorly understood. By integrating Cu and Al nanowires into non-local spin valves (NLSVs), spin and charge transport were separately characterized. We test a proposed generalization of the EY theory, where each scattering source is assigned a unique EY proportionality constant. Verification of the generalized EY theory and quantification of the EY constants for specific scattering sources (e.g., phonons, surfaces, grain boundaries, non-magnetic impurities, and local moments), then enables predictive spin relaxation models and improves understanding of specific spin relaxation sources in these model metals.