Room Temperature Mott Hopping and Spin pumping Characterization of Amorphous Gd-alloyed Bi2Se3

Disordered films have gained intense interest because of their possibility for spintronics applications by benefiting from other exotic transport properties. Here, we have fabricated disordered Gd-alloyed Bi_x Se_(1-x) (BSG) thin films by magnetron sputtering methods and have investigated their magneto-transport and spin-torque properties. Structural characterizations show a mainly amorphous feature for the 8nm thick BSG film, while Bi rich crystallites are developed inside the 16nm thick BSG film. The bulk resistivity of BSG film is found to be relatively high, up to 6x10^4 this http URL, with respect to the resistivity of the polycrystalline Bi_x Se_(1-x) film. Temperature dependent resistivity measurements display the evident character of a variable range hopping transport from 80K to 300K. Spin pumping transport characterizations have been performed on the BSG(t)/CoFeB(5 nm) bilayer structures with different thickness of BSG (t= 6, 8, 12, 16 nm). The possible various origins of the spin-to-charge conversion are related to extrinsic effects. Our study provides a new experimental direction, beyond crystalline solids, to the search for strong SOC systems in amorphous solids and other engineered random systems.