Structure of Ni-Mn-Ga films prepared by sputtering method

Makoto Ohtsuka, Kouki Chiba, Minoru Matsumoto, Kimio Itagaki

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

The properties of Ni-Mn-Ga films such as chemical composition, crystal structure, microstructure and transformation temperature were investigated with respect to sputtering conditions in the present study. The Ni-Mn-Ga films were deposited on a polyvinyl alcohol substrate with a radio-frequency magnetron sputtering apparatus using the Ni50Mn25Ga25 and Ni52Mn24Ga24 targets. After separating from the substrates, the films were annealed at the temperature between 873 and 1273 K for 3.6 ks. The chemical composition of the films depended on the radio-frequency generating power, however, there was no dependence on the heat treatment temperature. Each deposited film had a columnar grain structure. After heat treatment, the width of columnar grains widened and then became indistinct with increasing heat treatment temperature. The Heusler type cubic crystal structure of the film with heat treatment at 1073 K changed to the tetragonal one through the martensitic structural transformation during cooling. The martensitic structural transformation temperature increased with increasing nickel content of films, while the Curie temperature decreased. The film obtained at 200 W using the Ni52Mn24Ga24 target after heat treatment at 1073 K showed one-way shape memory effect through the reverse martensitic structural transformation during heating.

Original languageEnglish
Title of host publicationProceedings of the Second International Conference on Processing Materials for Properties
EditorsB. Mishra, C, Yamauchi, B. Mishra, C. Yamauchi
Pages301-306
Number of pages6
Publication statusPublished - 2000 Dec 1
EventProceedings of the Second International Conference on Processing Materials for Properties - San Francisco, CA, United States
Duration: 2000 Nov 52000 Nov 8

Publication series

NameProceedings of the Second International Conference on Processing Materials for Properties

Other

OtherProceedings of the Second International Conference on Processing Materials for Properties
CountryUnited States
CitySan Francisco, CA
Period00/11/500/11/8

ASJC Scopus subject areas

  • Engineering(all)

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  • Cite this

    Ohtsuka, M., Chiba, K., Matsumoto, M., & Itagaki, K. (2000). Structure of Ni-Mn-Ga films prepared by sputtering method. In B. Mishra, C. Yamauchi, B. Mishra, & C. Yamauchi (Eds.), Proceedings of the Second International Conference on Processing Materials for Properties (pp. 301-306). (Proceedings of the Second International Conference on Processing Materials for Properties).