Magnetic properties of as-cast R/sub 14/Fe/sub 78/C/sub 8/ (R=Pr, Nd, Sm) alloys

Structural and intrinsic properties of R/sub 14/Fe/sub 78/C/sub 8/ alloys, where R=Pr, Nd, and Sm, were studied experimentally. These compounds crystallize in a tetragonal structure of P42/mnm-type. The magnetization at room temperature and the Curie temperature are somewhat lower than those obtained in the corresponding R/sub 2/Fe/sub 14/B compounds. The anisotropy behavior of the compounds is very similar to that of R/sub 2/Fe/sub 14/B for R=Pr and Nd. However, a significant increase of both /sub i/H/sub c/ and sigma /sub r/ in Nd/sub 14/Fe/sub 78/C/sub 8/ is found as compared with Nd/sub 14/Fe/sub 78/B/sub 8/. The easy-cone type of anisotropy is unexpectedly observed in Sm/sub 14/Fe/sub 78/C/sub 8/ at both room temperature and low temperature. Spin reorientation at low temperature is observed for Nd/sub 14/Fe/sub 78/C/sub 8/ and Sm/sub 14/Fe/sub 78/C/sub 8/, and the transformation temperatures are determined to be about 115 K and 78 K, respectively.<
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