Abstract
Spinβtransfer torque exerted on a magnetic layer can be viewed as a linear response to the spin accumulation inside an adjacent nonβmagnetic layer, information about their response coefficient is provided by the complex spinβmixing conductance C^mix^. Substitutional disorder is known to affect the spinβdependent charge conductances and often reduces strongly the magnetoresistance. Here we examine its impact on C^mix^ of several selected realistic systems.
Recently predicted oscillations of C^mix^ as a function of ferromagnetic layer thickness in Ni based junctions might be suppressed by interface interdiffusion, but presented ab initio calculations disprove this possibility. Halfmetallic character of the Heusler compound Co~2~MnSi is destroyed by often encountered antisite disorder; however the impact of this disorder to the predicted C^mix^ is rather weak. Diluted magnetic semiconductor (Ga,Mn)As is an intrinsically disordered system, the analysis of calculations shows that the variation of C^mix^ with substitutional Mn content can be understood in terms of the associated change of the number of carriers, whereas the variation with lattice defects is more complex. (Β© 2008 WILEYβVCH Verlag GmbH & Co. KGaA, Weinheim)