Texture of Nd-Fe-B thin films prepared by magnetron sputtering

We have investigated the texture and magnetic properties of Nd12Fe88-xBx sputtered films with various boron contents, x. The c-axis orientation of Nd2Fe14B phase in the films was higher and the perpendicular coercive force became greater with increment of x. With more increment of x than 15, however, the coercive force decreased owing to formation of a large amount of amorphous soft magnetic phase. The transmission electron microscope observations revealed that highly c-axis oriented Nd12Fe71B17 film has a unique microstructure; oriented Nd2Fe14B phase and amorphous phase with widths of about 200 and 50 Angstrom, respectively, are alternately developed. This two-phase structure has realized an exchange coupled nanostructured magnet composed of aligned hard magnetic phase and soft magnetic phase. The maximum energy product of Nd12Fe71B17 film was estimated at 270 kJ/ m(3) with micromagnetic analysis assuming that the film was composed of complete regular structure. (C) 1999 American Institute of Physics. [S0021-8979(99)59808-3].