Manipulation of the magnetization in heavy-metal/ferromagnetic bilayers via the spin-orbit torque requires high spin Hall conductivity of the heavy metal. We measure inverse spin Hall voltage using a co-planar wave-guide based broadband ferromagnetic resonance set-up in Py/Ta system with varying crystalline phase of Ta. We demonstrate a strong correlation between the measured spin mixing conductance and spin Hall conductivity with the crystalline phase of Ta thin films. We found a large spin Hall conductivity of −2439(ℏ/e)Ω−1cm−1 for low-resistivity (68 μΩ−cm) Ta film having mixed crystalline phase, which we attribute to an extrinsic mechanism of the spin Hall effect.
@article{arxiv.1807.01127,
title = {Large spin current generation by the spin Hall effect in mixed crystalline phase Ta thin films},
author = {Akash Kumar and Rajni Bansal and Sujeet Chaudhary and P. K. Muduli},
journal= {arXiv preprint arXiv:1807.01127},
year = {2018}
}