Annealing studies of magnetron-sputtered CoCr thin films

Abstract

The microstructure and magnetic properties of annealed CoCr thin films of various thicknesses, deposited on glass substrates, were examined. In general, little grain growth upon annealing was observed. Low-angle grain boundaries, present in as-sputtered films of thickness [les]50 nm, were absent in annealed films. This occurs simultaneously with a decrease in the measured electrical resistivity. A reduction in the in-plane film stress occurs with annealing, correspondingly the experimentally measured anisotropy field values change markedly. A noticeable feature of the microstructure is the appearance of Cr-rich regions in annealed films 50 nm thick and above. These regions are thought to account for the observed increases in the saturation magnetization and coercivity with annealing time.