Spin accumulation effects in magnetoresistance of thin platinum films

Abstract

Thin platinum films were prepared by magnetron sputtering. It is found that when the field is along the current or perpendicular to both the current and the film plane, the magnetoresistance is positive while if the field is applied in the film plane perpendicular to the current, the magnetoresistance is negative. The temperature and thickness dependences of the positive and negative magnetoresistance are compared and the contribution due to the Hanle magnetoresistance is found. The thickness dependence of the Hanle magnetoresistance are analyzed within the framework of the theory of size effects in magnetoresistance caused by spin-orbit interaction. The value of the spin Hall angle in platinum is estimated.