Intermartensitic transitions and phase stability in Ni50Mn50−xSnx Heusler alloys. (15th October 2015)

• Record Type: Journal Article
• Authors: Çakır, Aslı; Righi, Lara; Albertini, Franca; Acet, Mehmet; Farle, Michael
• Is Part Of: Acta materialia. Volume 99(2015)
• Page Start: 140
• Page End: 149
• Publication Date: 2015-10-15
• Subjects: Heusler alloy -- Shape memory property -- Magnetism -- Phase diagram; Materials -- Periodicals; Materials science -- Periodicals; Materials -- Mechanical properties -- Periodicals; Metallurgy -- Periodicals; Chemistry, Inorganic -- Periodicals; 620.112
• DOI: 10.1016/j.actamat.2015.07.072
• Languages: English
• ISSNs: 1359-6454

Abstract

Abstract: Ni–Mn based Heusler alloys are of considerable interest due to their multifunctional properties such as magnetic shape memory, magnetocaloric effect and spintronics. The reason for these multifunctional properties is the presence of a first order martensitic transition and its strong coupling to the magnetization. In this work, one of the outstanding class of martensitic Heuslers, Ni–Mn–Sn, is investigated in relation to magneto-structural phase transitions and the stability of the various crystallographic structures under varying temperature. Temperature-dependent X-ray diffraction, resistance and magnetization measurements on Ni50 Mn50− x Sn x alloys are performed in a broad valence electron concentration range 7.91 ⩽ ( e / a ) ⩽ 8.34 ( 5.1 ⩽ x ⩽ 20.3 at . % ). The results reveal that in addition to the austenite–martensite transition, further intermartensitic transitions take place with decreasing temperature. Depending on the composition, we observe that the parent martensite phase tends to transform to L10 martensite as the ground state phase when the temperature is lowered. A phase diagram of Ni50 Mn50− x Sn x is constructed to include intermartensitic phase transition boundaries.