Crystallography and Microstructure of 7M Martensite in Ni-Mn-Ga Thin Films Epitaxially Grown on (1 1 2¯ 0)-Oriented Al2O3 Substrate

Materials

Bo Yang¹  Xiang Zhao¹  Haile Yan¹  Zongbin Li¹  Liang Zuo¹  Claude Esling²  Yudong Zhang² 

[1] Key Laboratory for Anisotropy and Texture of Materials (Ministry of Education), School of Material Science and Engineering, Northeastern University, Shenyang 110819, China;Laboratoire d’Étude des Microstructures et de Mécanique des Matériaux (LEM3), CNRS UMR 7239, Université de Lorraine, CEDEX, 57045 Metz, France;

关键词: Ni-Mn-Ga thin films;    magnetically-induced reorientation;    ferromagnetic shape memory alloys;    crystallography;   

DOI  :  10.3390/ma15051916

来源: DOAJ

【 摘 要 】

Epitaxial Ni-Mn-Ga thin films have been extensively investigated, due to their potential applications in magnetic micro-electro-mechanical systems. It has been proposed that the martensitic phase in the <1 1 0>_A-oriented film is much more stable than that in the <1 0 0>_A-oriented film. Nevertheless, the magnetic properties, microstructural features, and crystal structures of martensite in such films have not been fully revealed. In this work, the <1 1 0>_A-oriented Ni_51.0Mn_27.5Ga_21.5 films with different thicknesses were prepared by epitaxially growing on Al₂O₃(1 1 $\overline{2}$ 0) substrate by magnetron sputtering. The characterization by X-ray diffraction technique and transmission electron microscopy revealed that all the Ni_51.0Mn_27.5Ga_21.5 films are of 7M martensite at the ambient temperature, with their Type-I and Type-II twinning interfaces nearly parallel to the substrate surface.

【 授权许可】

Unknown