Transformation Volume Strain in Ni-Mn-Ga Thin Films

Authors

I. R. Aseguinolaza, University of the Basque Country
I. Reyes-Salazar, University of the Basque Country
A. V. Svalov, University of the Basque Country
K. Wilson, Boise State University
W. B. Knowlton, Boise State UniversityFollow
P. Müllner, Boise State UniversityFollow
J. M. Barandiárn, University of the Basque Country
E. Villa, CNR-IENI
V. A. Chernenko, University of the Basque Country

Document Type

Article

Publication Date

12-12-2012

Abstract

The temperature dependences of the lattice parameters and residual stress have been measured for a fine-grained Ni_52.2Mn_26.8Ga_21.0 (at. %) thin film fabricated by sputter deposition onto a heated silicon wafer with SiN_x buffer layer. The transformation volume strain in the film was found to be a lattice expansion during the forward martensitic transformation which is opposite to a volume contraction exhibited by bulk Ni-Mn-Ga alloys. This unusual effect can be explained by the substrate-induced residual stresses in the film and the difference in the elastic modulus of austenite and martensite.

Publication Information

Aseguinolaza, I. R.; Reyes-Salazar, I.; Svalov, A. V.; Wilson, K.; Knowlton, W. B.; Müllner, P.; Barandiárn, J. M.; Villa, E.; and Chernenko, V. A.. (2012). "Transformation Volume Strain in Ni-Mn-Ga Thin Films". Applied Physics Letters, 101(24), 241912-1 - 241912-4. https://doi.org/10.1063/1.4772005