|
Although there has been enormous development in the field of spintronics, it is a challenge to interpret the experimental results and estimate the key parameters e.g., spin diffusion length. While designing functional devices, it creates a severe issue since an inaccurate estimation of one parameter also affects the estimation of other parameters concomitantly. The spin diffusion length of a giant spin-orbit material platinum (Pt) has been reported in literature in a wide range of 0.5 - 14 nm, and it is usually treated as a constant value independent of Pt's thickness. For an accurate estimation of spin diffusion length, noting that circuit theory has been tremendously successful in translating physical equations into circuit elements in organized form, we construct the spin-circuit representation of spin pumping. Thereby it is shown clearly that a thickness-dependent conductivity and spin diffusion length is necessary to simultaneously match the experimental results of effective spin mixing conductance and inverse spin Hall voltage due to spin pumping. Such thickness-dependent spin diffusion length is tantamount to Elliott-Yafet spin relaxation mechanism and it bodes well for transitional metals. It is also shown that this conclusion is not altered when there is a significant interfacial spin memory loss.
|
