EFFECT OF SILICON SUBSTITUTION ON THE MAGNETIC-PROPERTIES OF TB2FE17 SINGLE-CRYSTALS

The growth of single crystals Tb2Fe17-xSix (x = 0, 1, 2, 3, and 3.3) b y the Czochralski method is performed. The crystal structure and magne tic properties are investigated. The substitution of silicon for iron leads to the reduction of the lattice parameters, and the significant increase of the Curie temperature from 413 to 526 K. The mean field an alysis shows that the Fe-Fe exchange interaction is much strengthened while the Tb-Fe one is slightly weakened by the introduction of silico n. The anisotropy constants up to the sixth order are calculated by fi tting the magnetization process of the samples at 1.5 K under the fiel d up to 65 kOe. In addition, a narrow domain wall pinning-dominated pr ocess caused by the substitution of Si for Fe is confirmed and analyze d. (C) 1998 American Institute of Physics.