We demonstrate the injection and detection of electrically and thermally generated spin currents probed in Co2MnSi/Cu lateral spin valves. Devices with different electrode separations are patterned to measure the non-local signal as a function of the electrode spacing and we determine a relatively high effective spin polarization α of Co2MnSi to be 0.63 and the spin diffusion length of Cu to be 500 nm at room temperature. The electrically generated non-local signal is measured as a function of temperature and a maximum signal is observed for a temperature of 80 K. The thermally generated non-local signal is measured as a function of current density and temperature in a second harmonic measurement detection scheme. We find different temperature dependences for the electrically and thermally generated non-local signals, which allows us to conclude that the temperature dependence of the signals is not just dominated by the transport in the Cu wire, but that there is a crucial contribution from the different generation mechanisms, which has been largely disregarded to date.
@article{arxiv.1507.04868,
title = {Spin Currents injected electrically and thermally from highly spin polarized Co$_2$MnSi},
author = {Alexander Pfeiffer and Shaojie Hu and Robert M. Reeve and Alexander Kronenberg and Martin Jourdan and Takashi Kimura and Mathias Kläui},
journal= {arXiv preprint arXiv:1507.04868},
year = {2015}
}