Mössbauer study of amorphous Nd−Fe−B films and their crystallization processes

Amorphous Nd−Fe−B films prepared by rf sputtering and their crystallization processes have been investigated by Mossbauer spectroscopy. A preferable alignment of the magnetization was observed in the amorphous film with a low hyperfine field of 173 kOe. With crystallization the average hyperfine field increases sharply, and the preferable alignment of the magnetization vanishes rapidly. The spectrum of the sample annealed at 750°C with coercivityHc=15.7 kOe shows that only Nd2Fe14B phase exists.