Preparation, microstructure, and magnetic properties of bulk nanocrystalline Gd metal

Bulk nanocrystalline gadolinium metal was prepared using spark plasma sintering (SPS) and subsequent annealing process. The SPS Gd metal had a single phase with a mean grain size of about 10 nm. A pressure-induced C-axis crystal texture was found in the SPS Gd sample. With the decrease of Gd grains from micrometer to nanometer range, the Curie temperature T-C decreased by 10.7 K and the magnetic moment per Gd atom at 5 K dropped noticeably from 7.81 mu(B) to 6.31 mu(B). These results indicate the remarkable influence of the nanostructure on the magnetism of Gd due to the finite size effect. (c) 2006 American Institute of Physics.