EXAFS Study for Mechanically Alloyed Co₅₀C₅₀

Abstract

Co₅₀C₅₀ alloys were fabricated by mechanical alloying process from the mixed powder of pure cobalt and carbon. The variations of the local structure and magnetic properties were examined by EXAFS analysis and the VSM magnetometer. It is shown that the alloying was progressed as the milling time increases. The significant changes of the magnetization and the structure has been occured in 12 h milling. EXAFS spectrum and its Fourier transform confirms that the final product is in the amorphous state. The EXAFS spectrum of the alloy milled for 24 h was fitted to the conventional EXAFS equation. The interatomic distances obtained from the fitting were 1.94 ± 0.02 Å for Co-C pair and 2.52 ± 0.02 Å for Co-Co pair, respectively. The magnetization was almost saturated in 24 h milling.