RESONANT ULTRASOUND MEASUREMENTS OF ELASTIC-CONSTANTS IN MELT-SPUN R2FE14B COMPOUNDS (R=CE, PR, ND, ER)

Measurements are reported of the longitudinal and transverse elastic m oduli of the R2Fe14B compounds having rare-earth component R=Ce, Pr, N d, and Er. A resonant ultrasound technique was used to determine the e lastic constants on hot-pressed, melt-spun samples which are essential ly isotropic, polycrystalline specimens of the four compounds. The res ults for Nd2Fe14B, which agree well with previous studies, and Er2Fe14 B exhibit clear signatures of the spin reorientations which occur in t hose compounds. No such signature appears in the data for Pr2Fe14B, co nsistent with the fact that no spin reorientation occurs in that mater ial. The ultrasonic attenuation of each sample has also been measured and it has been found that it shows features in the vicinity of spin r eorientations (Nd2Fe14B, Er2Fe14B) and the Curie point (Ce2Fe14B).