Strain behavior and lattice dynamics in Ni50Mn35In15. (29th September 2015)

• Record Type: Journal Article
• Authors: Salazar Mejía, C; Nayak, A K; Schiemer, J A; Felser, C; Nicklas, M; Carpenter, M A
• Is Part Of: Journal of physics. Volume 27:Number 41(2015)
• Publication Date: 2015-09-29
• Subjects: Heusler alloys -- resonant ultrasound spectroscopy -- martensitic transition; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/0953-8984/27/41/415402
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: The lattice dynamics in the polycrystalline shape-memory Heusler alloy Ni50 Mn35 In15 have been studied by means of resonant ultrasound spectroscopy (RUS). RUS spectra were collected in a frequency range 100–1200 kHz between 10 and 350 K. Ni50 Mn35 In15 exhibits a ferromagnetic transition at 313 K in the austenite phase and a martensitic transition at 248 K accompanied by a change of the magnetic state. Furthermore it displays a paramagnetic to ferrimagnetic transition within the martensitic phase. We determined the temperature dependence of the shear modulus and the acoustic attenuation of Ni50 Mn35 In15 and compared it with magnetization data. Following the structural softening, which accompanies the martensitic transition as a pretransitional phenomenon, a strong stiffening of the lattice is observed at the martensitic magneto-structural transition. Only a weak magnetoelastic coupling is evidenced at the Curie temperatures both in austenite and martensite phases. The large acoustic damping in the martensitic phase compared with the austenitic phase reflects the motion of the twin walls, which freezes out in the low temperature region.