Magnetoresistance Effect of Granular Films Employing Co₂FeAl_0.5Si_0.5 Alloy

Abstract

Magnetoresistance (MR) effects and electroric structure were investigated for granular films employing Co₂FeAl_0.5Si_0.5 (CFAS) alloy. CFAS-MgO granular films showed a maximum MR ratio of approximately 4.8 %. It was however recognized that the surface of CFAS granules was slightly oxidized due to the low formation energy of MgO matrix. By utilizing MgF₂ matrix, the MR ratio increased to approximately 6.5 %. After annealing at 200°C, the MR ratio increased slightly. It was thought that the L2₁ ordered structure was not obtained due to the low annealing temperature. Further annealing at high temperature is required to obtain L2₁ ordered CFAS granules.