Single crystal neutron diffraction investigations of the crystal and magnetic structures of R2Fe14B (R=Y, Nd, Ho, Er)

The compounds of general formula R2Fe14B form a series of magnetic material s, the prototype of which, Nd2Fe14B, is used to make high performance perma nent magnets. These compounds crystallise in the tetragonal space group P4( 2)/mnm and with R=Nd, Ho, Er, Tm and Yb a spin reorientation transition was found. Precise structural analyses using neutron diffraction on single cry stals were undertaken. It is clearly demonstrated that lowering of symmetry takes place for non-axial compounds. Besides, large deviations to collinea rity of the magnetic an arrangements were determined. (C) 2001 Elsevier Sci ence B.V. All rights reserved.