(0391)Enhancement of L21-chemical ordering in half-metallic Heusler compound Co_2MnSi by Ag doping

摘要

A class of materials called half-metallic Heusler compound, especially Cobalt-based Co2YZ (Y = Mn, Fe, and Z= Si, Ge, Al etc.) compounds have attracted much attention in the recent growing development of spintronics due to the observation of large giant magnetoresistance (GMR)1) and tunnel magnetoresistance (TMR)2) ratios. The full-Heusler compounds crystallized in the L21 structure (X2YZ), may also grow in B2 and A2 structures depending on the disordered state, in which (Y, Z) and (X, Y, Z) are randomly substituted. Enhancement of spin polarization by improving chemical ordering, and reduction of ordering temperature are crucial issues for the further development of spintronic devices using Heusler compounds. In this study we have investigated the effect of doping of Ag on the enhancement of chemical ordering in Heusler compound Co_2MnSi(CMS) since Ag does not mix with CMS.