Spin injection into silicon detected by broadband ferromagnetic resonance spectroscopy

• DOI: 10.1063/1.4983012
• Publication Date: 2017-05-02T15:00:55Z
• Authors: Ryo Ohshima; Stefan Klingler; Sergey Dushenko; Yuichiro Ando; Mathias Weiler; Hans Huebl; Teruya Shinjo; Sebastian T. B. G...; Masashi Shiraishi
• Keywords: Condensed Matter - Other Condensed Matter; Accelerator Physics (physics.acc-ph); Condensed Matter - Materials Science; 0103 physical sciences; Materials Science (cond-mat.mtrl-sci); FOS: Physical sciences; Physics - Accelerator Physics; Physics - Applied Physics; Applied Physics (physics.app-ph); 01 natural sciences; Other Condensed Matter (cond-mat.other)

We studied the spin injection in a NiFe(Py)/Si system using broadband ferromagnetic resonance spectroscopy. The Gilbert damping parameter of the Py layer on top of the Si channel was determined as a function of the Si doping concentration and Py layer thickness. For a fixed Py thickness, we observed an increase in the Gilbert damping parameter with decreasing resistivity of the Si channel. For a fixed Si doping concentration, we measured an increasing Gilbert damping parameter for decreasing Py layer thickness. No increase in the Gilbert damping parameter was found for Py/Si samples with an insulating interlayer. We attribute our observations to an enhanced spin injection into the low-resistivity Si by spin pumping.