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Observation and characterization of a twinned monoclinic phase as a product of the solid state decomposition of Nd2Fe14B

Published online by Cambridge University Press:  31 January 2011

L. Rabenberg ,
Josef Fidler  and
Johannes Bernardi
L. Rabenberg*
Affiliation:
Institut für Angewandte und Technische Physik, Technische Universität Wien, Wiedner Hauptstraβe 10-8/137, A-1040 Wien, Austria
Josef Fidler
Affiliation:
Institut für Angewandte und Technische Physik, Technische Universität Wien, Wiedner Hauptstraβe 10-8/137, A-1040 Wien, Austria
Johannes Bernardi
Affiliation:
Institut für Angewandte und Technische Physik, Technische Universität Wien, Wiedner Hauptstraβe 10-8/137, A-1040 Wien, Austria
*
a)Permanent address: Center for Materials Science and Engineering, The University of Texas at Austin, Austin, Texas 78712.
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Abstract

A microtwinned monoclinic phase is observed to occur within the grains of the hard magnetic phase in Nd2Fe14B-based permanent magnet alloys. This phase seems to be the product of a displacive solid state phase transformation of tetragonal Nd2Fe14B, distinguished from Nd2Fe14B by the presence of an ordered substitution into alternating unit cells parallel to the crystallographic c-axis and by a small shear of the type 〈100〉 {011}. The four different orientational variants of this monoclinic phase with respect to the parent tetragonal phase are arranged into two distinct colonies of twin-related plates. The observation that Nd2Fe14B can undergo a displacive solid state transformation has broad implications for the entire field of Nd2Fe14B permanent magnets.

Type
Articles
Information
Journal of Materials Research , Volume 7 , Issue 7 , July 1992 , pp. 1762 - 1768
Copyright
Copyright © Materials Research Society 1992

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