Correlative multi-scale characterization of a fine grained Nd-Fe-B sintered magnet

T T Sasaki; T Ohkubo; K Hono; Y Une; M Sagawa

doi:10.1016/j.ultramic.2013.01.006

Correlative multi-scale characterization of a fine grained Nd-Fe-B sintered magnet

Ultramicroscopy. 2013 Sep:132:222-6. doi: 10.1016/j.ultramic.2013.01.006. Epub 2013 Feb 11.

Authors

T T Sasaki¹, T Ohkubo, K Hono, Y Une, M Sagawa

Affiliation

¹ National Institute for Materials Science, 1-2-1 Sengen, Tsukuba, Ibaraki 305-0047, Japan. Electronic address: sasaki.taisuke@nims.go.jp.

PMID: 23477852
DOI: 10.1016/j.ultramic.2013.01.006

Abstract

The Nd-rich phases in pressless processed fine grained Nd-Fe-B sintered magnets have been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and three dimensional atom probe tomography (3DAP). The combination of the backscattered electron (BSE) and in-lens secondary electron (IL-SE) images in SEM led to an unambiguous identification of four types of Nd-rich phases, NdOx, Ia3 type phase, which is isostructural to Nd₂O₃, dhcp-Nd and Nd₁Fe₄B₄. In addition, the 3DAP analysis of thin Nd-rich grain boundary layer indicate that the coercivity has a close correlation with the chemistry of the grain boundary phase.

Keywords: 3DAP; Multi-scale characterization; SEM; TEM.

Publication types

Research Support, Non-U.S. Gov't