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Article
Magnetic Tweed Contrast In Ferromagnetic Shape Memory Alloys
Microscopy and Microanalysis
  • Marc De Graef, Carnegie Mellon University
  • S. Venkateswaran, Carnegie Mellon University
  • Yoichi Kishi, University of Maryland, College Park
  • Thomas A. Lograsso, Iowa State University
  • D. Viehland, Virginia Polytechnic Institute and State University
  • Manfred Wuttig, University of Maryland, College Park
Document Type
Article
Publication Date
8-1-2003
DOI
10.1017/S143192760344292X
Abstract

Recently, ferromagnetic martensite, specifically ferromagnetic shape memory alloys (FMSMAs), have received renewed attention because of their large domain motion induced magnetostrictive strains. In the low temperature phase of these alloys, 90◦ magnetic domain walls are simultaneously elastic twin boundaries. Above the temperature at which these alloys undergo a near second order martensitic transformation, their microstructure as observed by two-beam TEM methods, consists of the well known tweed contrast. This structure represents a random mixture of incipient twins of the martensitic phase. The transformation hysteresis of Co-Ni-Ga FMSMAs is quite small. In addition, the alloy is elastically soft similar to others that undergo a near second order martensitic transformation. Therefore, it is possible that magnetic tweed be observed in this alloy. This paper reports on its observation by conventional TEM, electron diffraction and Lorentz microscopy.

Comments

This article is from Microscopy and Microanalysis 9 (2003): pp. 584—585, doi:10.1017/S143192760344292X

Copyright Owner
Microscopy Society of America
Language
en
File Format
application/pdf
Citation Information
Marc De Graef, S. Venkateswaran, Yoichi Kishi, Thomas A. Lograsso, et al.. "Magnetic Tweed Contrast In Ferromagnetic Shape Memory Alloys" Microscopy and Microanalysis Vol. 9 Iss. Suppl. 2 (2003) p. 584 - 585
Available at: http://works.bepress.com/thomas_lograsso/173/