Random anisotropy model approach on ion beam sputtered Co20Cu80 granular alloy

The Co20Cu80 granular film has been elaborated using ion beam sputtering technique. The magnetic properties of the sample were studied in the temperature range 5-300 K at H less than or equal to 50 kOe. From the thermomagnetisation curve, which is found to obey to the Bloch law, we have extracted the spin wave stiffness constant D and the exchange constant A. The magnetic experimental results have been interpreted in the framework of random anisotropy model. We have determined the local anisotropy constant K-L and the local correlation length of anisotropy axis R-a which is compared to the experimental grains size obtained by transmission electronic microscopy. (C) 2002 Elsevier Science B.V. All rights reserved.