Microstructural investigations of fine grain Co-Hf-C films

Microstructural investigations have been performed on Co-Hf-C films which show high mu (>2000), high Bs (1.4 T), and high thermal stability (>700 degrees C). The magnetic properties are very sensitive to the volume fraction of HfC particles. After annealing at 700 degrees C, Co-Hf-C films of the optimum composition consist of a mixture of fine FCC-Co and HfC grains. The grain size of FCC-Co is 10 approximately 15 nm and that of HfC is 3 approximately 4 nm. The HfC particles are located at the grain boundaries of FCC-Co. HfC was found to crystallize before the FCC-Co, and the fine dispersion of these particles successfully inhibited the grain growth of the FCC-Co.<
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