Characteristics of 5M modulated martensite in Ni-Mn-Ga magnetic shape memory alloys

• DOI: 10.1063/1.4932233
• Publication Date: 2015-09-29T17:01:41Z
• Authors: A. Çakır; M. Acet; L. Righi; F. Albertini; M. Farle
• Keywords: Magnetic shape-memory alloy; Modulation (music); Lattice (music)

The applicability of the magnetic shape memory effect in Ni-Mn-based martensitic Heusler alloys is closely related to nature crystallographically modulated martensite phase these materials. We study properties phases as a function temperature and composition three Ni49.8Mn25.0Ga25.2, Ni49.8Mn27.1Ga23.1 Ni49.5Mn28.6Ga21.9. substituting Ga for Mn leads an anisotropic expansion lattice, where b-parameter 5M structure increases c-parameters decrease with increasing concentration. modulation vector found be both dependent. size corresponds incommensurate Ni49.8Mn25.0Ga25.2 at all temperatures. For other samples low temperatures but reaches commensurate value q ≈ 0.400 close room temperature. results show that commensurateness special case particular