Structure and Magnetoresistance of Granular Ferromagnets (Co_(50)Fe_(50))_x-Ag_(1-x) and (Co_(50)Fe_(50))_x-(Al_2O_3)_(1-x)

摘要

A comparative study of the structure, magnetoresistive and magnetic properties in two types of granular thin film ferromagnets: ferromagnet-nonmagnetic metal (Co_(50)Fe_(50))_x-Ag_(1-x) and ferromagnetic metal -insulator (Co_(50)Fe_(50))_x-(Al_2O_3)_(1-x) (x is volume fraction) is reported. Giant (GMR) and tunnel (TMR) magnetoresistance are found in the both systems below the magnetic metal percolation threshold. The GMR and TMR effects and magnetic properties of the investigated systems are shown to be essentially independent on the nature of nonmagnetic matrix.