Extensive study of giant magnetoresistance properties in half-metallic Co_2(Fe,Mn)Si-based devices

摘要

Fully epitaxial Co_2Fe_xMn_(1-x)Si(CFMS)/Ag/Co_2Fe_xMn_(1-x)Si current-perpendicular-to-plane giant magnetoresistive devices with various Fe/Mn ratios x and top CFMS layer thicknesses t_(CFMS) were prepared. The highest magnetoresistance (MR) ratios, 58% at room temperature and 184% at 30 K, were observed in the sample with x = 0.4 and t_(CFMS) = 3 nm. Enhancement of interface spin-asymmetry was suggested for x = 0.4 compared with that at x = 0. A MR ratio of 58% was also observed even in a very thin trilayer structure, CFMS(4 nm)/Ag(3 nm)/CFMS(2 nm), which is promising for a next-generation magnetic read sensor for high-density hard disk drives.