DIRECTIONAL SOLIDIFICATION AND MAGNETIC-PROPERTIES OF MNSB SB EUTECTIC COMPOSITE

The microstructures, solidification behaviour, crystal orientation and magnetic properties of MnSb-Sb eutectic with a high entropy of soluti on have been studied systematically. The present approach reveals the inherent correlations between them. MnSb-Sb eutectic is characterized by a non-faceted-non-faceted type of growth and well-distributed align ed MnSb rods embedded in a Sb matrix on a micron scale, an ideal compo site structure, during directional solidification. The scaling laws of the variation in interrod spacing lambda (or rod diameter d) with gro wth velocity are quantitatively developed. A parallel orientation rela tion between [001] of MnSb and rod axis is identified through electron diffraction patterns, indicating that the highly anisotropic composit e has been fabricated successfully. The hysteresis loops of directiona lly solidified MnSb-Sb composites are determined along the MnSb rod ax is. The saturation magnetization and constant permeability have been e valuated by considering the alignment, size and magnetocrystalline ani sotropy. (C) 1998 Chapman & Hall.