Evidence of adaptive modulation and magnetic field induced reorientation of variants in epitaxially grown Ni-Mn-Ga thin film on Al 2 O 3 (112¯0) substrate

Sharma, A and Mohan, S and Suwas, S (2019) Evidence of adaptive modulation and magnetic field induced reorientation of variants in epitaxially grown Ni-Mn-Ga thin film on Al 2 O 3 (112¯0) substrate. In: Materials Science and Engineering B: Solid-State Materials for Advanced Technology, 242 . pp. 6-16.

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Abstract

Epitaxial Ni-Mn-Ga thin films with a room temperature martensite phase were fabricated on single crystal Al 2 O 3 (112¯0) substrate using direct current (DC) magnetron sputtering. The X-ray pole figure measurements confirm the epitaxial relationship of Ni-Mn-Ga (101) 7M || Al 2 O 3 (112¯0) and Ni-Mn-Ga 101¯ 7M || Al 2 O 3 11¯01 between the film and substrate. Transmission electron microscopy reveals the presence of (220) micro-twins at an angle of 62.5° and 56.3° with respect to (202) growth plane. Coexistence of non-modulated martensite phase (a NM = 5.45 à and c NM = 6.56 à ) and seven modulated martensite phases (a 14M =6.26à ,b 14M =5.89à andc 14M =5.56à ) has been observed in the film. The in-situ high-temperature X-ray diffraction indicates reversible thermal phase transformation in the film with a very low thermal hysteresis. The magnetic field induced reorientation (MIR) effect is displayed by the film. © 2019

Item Type:	Journal Article
Publication:	Materials Science and Engineering B: Solid-State Materials for Advanced Technology
Publisher:	Elsevier Ltd
Additional Information:	Copyright for this article belongs to Elsevier Ltd
Keywords:	Adaptive modulation; Alumina; Aluminum oxide; High resolution transmission electron microscopy; Magnetic fields; Martensite; Martensitic transformations; Single crystals; Sputtering; Ternary alloys, Direct current magnetron sputtering; Epitaxial relationships; Epitaxial thin films; High temperature X-ray diffraction; Martensitic phase transformations; Ni-Mn-Ga thin films; Thermal hysteresis; X-ray pole figure measurement, Thin films
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy) Division of Interdisciplinary Sciences > Centre for Nano Science and Engineering
Date Deposited:	08 Apr 2019 11:22
Last Modified:	08 Apr 2019 11:22
URI:	http://eprints.iisc.ac.in/id/eprint/62002

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