Heusler alloys for Spin Transport
Abstract: It has been widely appreciated that Heusler alloys (e.g., Co2MnSi) can be half-metallic, meaning that there is a gap for one spin state at the Fermi level. It is in principal possible to use this feature to generate currents that are 100% spin-polarized. Unfortunately, exploiting this characteristic in real devices, which necessarily include interfaces between dissimilar materials, represents a far greater challenge. This seminar will focus on observations about epitaxial Heusler alloys grown on GaAs and MgO. I will discuss why we are interested in the microwave properties of these heterostructures as well as their interfacial spin-polarization. This will include a discussion of new techniques for probing spin accumulation using ferromagnetic resonance as well as some mysteries we have encountered in attempting to measure the limits on the damping of magnetic resonance in epitaxial films.