Title :
Analytical microscope studies of sintered Nd-Fe-B magnets
Author_Institution :
Technical University, Karlsplatz, Vienna, Austria
fDate :
9/1/1985 12:00:00 AM
Abstract :
Various sintered Nd15Fe77B8permanent magnets supplied by different producers have been examined by analytical electron microscopy. An identical microstructure was found in all of the different magnets. Three phases were detected by means of high resolution electron microscopy, electron diffraction and x-ray microanalysis. Besides the hard magnetic boride phase Nd2Fe14B, a soft magnetic boride phase close to Nd2Fe7B6, and a Nd-rich sintering aid phase (d.h.c.p. structure) were identified. The Nd-rich phase preferentially occurs along grain boundaries as a thin layer with about 10 nm tickness. The soft magnetic phases determine the magnetization reversal and limit the coercivity of sintered Nd-Fe-B magnets.
Keywords :
Permanent magnets; Electron microscopy; Iron; Magnetic analysis; Magnetic force microscopy; Microstructure; Neodymium; Permanent magnets; Phase detection; Soft magnetic materials; X-ray detection;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.1985.1063992