Modifying the nanostructure of Co[Si[O.sub.2]] samples by controlled annealing

In situ measurements of resistance were made on cosputtered [Co.sub.0.35][[Si[O.sub.2].sub.0.65]] granular films during annealing. The aim is to control the thermal treatment parameters and map the microstructural changes of the samples, with the respective magnetotransport response. Results of transmission electron microscopy, dc magnetization, and temperature dependence of resistivity, after annealing, show a clear evolution in the nanostructure of the samples, with increasing average Co grain sizes and wider dispersion. Index Terms--Heat treatment, magnetic films, magnetoresistance.