Magnetic anisotropy of Nd15Fe77B8 flakes made by twin-roller quenching

Abstract

Rapid solidification by twin-roller quenching of iron-neodymium-boron alloys produces flakes which show a strong (00l) texture normal to their surface by x-ray diffraction. The strong crystal orientation is argued to be due to both directional solidification in a thermal gradient and uniaxial deformation of the solid phase in the twin rollers. Magnetization studies on individual flakes show intrinsic coercivities of 14 kOe and a nearly 50% higher remanance for field normal to the flake surface (Br =9.5 kG) than in the flake plane (Br =6.5 kG). The perpendicular (BH)max is 16 MG Oe.