Martensite structures and twinning in substrate-constrained epitaxial Ni-Mn-Ga films deposited by a magnetron co-sputtering process

Jérémy Tillier (1, 2) , Daniel Bourgault (3, 1) , Sébastien Pairis (4) , Luc Ortega (5) , Nathalie Caillault (2) , Laurent Carbone (2)

1 CRETA - Consortium de Recherches pour l'Emergence des Technologies Avancées
2 SE - Schneider Electric
3 NEEL - TPS - Thermodynamique et biophysique des petits systèmes
4 NEEL - C2MA - Croissance Cristalline et MicroAnalyse
5 NEEL - X'Press - X'Press : diffraction et hautes pressions

In order to obtain Ni-Mn-Ga epitaxial films crystallized in martensite structures showing Magnetic-Induced Rearrangement (MIR) of martensite variants, a fine control of the composition is required. Here we present how the co-sputtering process might be helpful in the development of Ni-Mn-Ga epitaxial films. A batch of epitaxial Ni-Mn-Ga films deposited by co-sputtering of a Ni-Mn-Ga ternary target and a pure manganese target has been studied. The co-sputtering process allows a precise control of the film compositions and enables keeping the epitaxial growth of Ni-Mn-Ga austenite during deposition at high temperature. It gives rise to tune the content of the MIR-active 14-modulated martensite in the film at room temperature, as well as micro and macro-twinned domains sizes.

Mots clés: Ni-Mn-Ga Magnetic Shape Memory Alloy; Thin film; Epitaxial growth; Structure; Deposition by co-sputtering

Domaines: Science des matériaux [cond-mat.mtrl-sci]

Jérémy Tillier, Daniel Bourgault, Sébastien Pairis, Luc Ortega, Nathalie Caillault, et al.. Martensite structures and twinning in substrate-constrained epitaxial Ni-Mn-Ga films deposited by a magnetron co-sputtering process. Physics Procedia, 2010, 10, pp.168-173. ⟨10.1016/j.phpro.2010.11.094⟩. ⟨hal-00555891⟩