间隙碳原子对(Er_(1-x)Sm_x)_2Fe_(17)C_y化合物形成、结构与磁性的影响

INFLUENCE OF INTERSTITIAL CARBON ATOMS ON FORMATION, STRUCTURE AND MAGNETIC PROPERTIES OF (Er_(1-x)Sm_x)_2Fe_(17)C_y COMPOUNDS

用快淬方法制备了单相(Er_(1-x)Sm_x)_2Fe_(17)C_y(x=0.2,<3.0;x=0.5,y<2.0)化合物,研究了它们的形成、结构、稳定性及内禀磁性结果表明,它们在高温是稳定的,随碳含量的增加,晶体结构由六角的Th_2Ni_(17)型向菱方的Th_2Zn_(17)型转变间隙碳原子的引入导致了单胞体积的膨胀、室温饱和磁化强度和Curie温度的增加当y>1.0时,(Er_(1-x)Sm_x)_2Fe_(17)

The (Er_(1-x)Sm_x)_2Fe_(17)C_y(x=0.2, y≤3.0; x=0.5, y≤2.0) compounds with a 2:17-type single phase structure were prepared by melt-spinning. The formation, structure, stability and intrinsic magnetic properties of these carbides were studied. The experimental re- sults show that these carbidek are stable at high temperatures. With increasing carbon concen- tration x, their crystal structure changes from the hexagonal Th_2Ni_17-type to rhombohedral Th_2Zn_(17)-type. The introduction of interstitial carbon atoms results in the expansion of the unit cell volumes and the increase of the room temperature saturation magnetization and Curie temperature. The (Er_(1-x)Sm_x)_2Fe_17C_y carbides with y≥1.0 are found to have an easy c-axis anisotropy at room temperature.