Observation of solid-state amorphization in the immiscible system Cu-Ta

The Cu-Ta system has been known to be immiscible and never amorphized by the conventional rapid quenching technique. The possibility of solid-state amorphization of Cu30 Ta70 during mechanical alloying (MA) was examined by the local structure observation using extended x-ray absorption fine structure (EXAFS). It was found that long-range order around Cu and Ta atoms gradually disappeared as a result of MA. These results are also important to an understanding of the reaction mechanism of amorphization during MA.