Search for content and authors

Stress-temperature relationship in a Ni-Mn-Ga single crystal

Eduard Cesari 2Volodymyr A. Chernenko 3J Pons 2K Ishikawa 1

1. Tohoku Gakuin University, Tagajo, Japan
2. Departament de Fisica, Universitat de les Illes Balears (UIB), Ctra. de Valldemossa, km. 7.5, Palma de Mallorca E07122, Spain
3. Institute of Magnetism, N.A.S. of Ukraine, 36-b Vernadsky Blvd, Kyiv 252142, Ukraine


Off-stoichiometric Ni-Mn-Ga Heusler alloys exhibit a large variety of martensitic structures as well as several accompanying phenomena, as precursor or pre-martensitic effects and inter-martensitic transformations (IMT). Both the ferromagnetic and the paramagnetic martensites tend to exhibit stress- and temperature- induced IMT. Three main martensitic phases are formed, namely 10M, 14M and 2M in the monoclinic coordinate system or, in cubic coordinates, designed as five-layer modulated tetragonal (c/a <1), seven-layer orthorhombic and non-modulated tetragonal (c/a>1), respectively.

The sequence of thermally and stress-induced inter-martensitic transformations has been studied in a Ni52.0-Mn24.4-Ga23.6 single crystal. Transmission electron microscopy through in situ cooling experiments has confirmed the thermally induced martensitic phases and their sequence. The stress-strain behavior under compression along the <110>P and <100>P crystallographic directions, at different temperatures, has also been studied for this compound and a stress-temperature phase diagram has been established.


Legal notice
  • Legal notice:

Related papers

Presentation: poster at E-MRS Fall Meeting 2005, Symposium C, by Eduard Cesari
See On-line Journal of E-MRS Fall Meeting 2005

Submitted: 2005-05-19 10:37
Revised:   2009-06-07 00:44