Determination of the fraction of t-Fe3B in hydrogen disproportionated Hf-doped NdFeB alloy by Mössbauer spectroscopy

F.D. SACCONE, F.H. SANCHEZ, C. RODRIGUEZ TORRES, B. GEBEL, O. GUTFLEISCH

JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2001 vol. 226 p. 1461 - 1463

0304-8853

NdFeB alloys processed by solid hydrogenation}disproportionation treatments between 7053C and 9503C were studied by MoK ssbauer spectroscopy. This technique is shown to be suitable to detect and quantify the presence of the intermediate tetragonal FeB phase formed during this process which is considered to be responsible for the preservation of Nd FeB crystal anisotropy. It was found that for 30 min treatments at 730}8503C, the fraction of Fe in t-FeB remained between 12% and 15%, while less than 5% was in the competing boride Fe B. The fraction of t-FeB was larger for shorter treatments.