Optical and magneto-optical studies of martensitic transformation in Ni-Mn-Ga magnetic shape memory alloys

Journal Article · Thu May 07 00:00:00 EDT 2015 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4917059· OSTI ID:22409941

Beran, L.; Cejpek, P.; Kulda, M.; Antos, R.; Holy, V.; Straka, L. ^[1]; Heczko, O. ^[2]

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1. Laboratory of Engineering Materials, Aalto University, PL 14200, FIN-00076 Aalto (Finland)
2. Institute of Physics ASCR, Na Slovance 2, 18221 Prague (Czech Republic)

Optical and magneto-optical properties of single crystal of Ni{sub 50.1}Mn{sub 28.4}Ga{sub 21.5} magnetic shape memory alloy during its transformation from martensite to austenite phase were systematically studied. Crystal orientation was approximately along (100) planes of parent cubic austenite. X-ray reciprocal mapping confirmed modulated 10 M martensite phase. Temperature depended measurements of saturation magnetization revealed the martensitic transformation at 335 K during heating. Magneto-optical spectroscopy and spectroscopic ellipsometry were measured in the sample temperature range from 297 to 373 K and photon energy range from 1.2 to 6.5 eV. Magneto-optical spectra of polar Kerr rotation as well as the spectra of ellipsometric parameter Ψ exhibited significant changes when crossing the transformation temperature. These changes were assigned to different optical properties of Ni-Mn-Ga in martensite and austenite phases due to modification of electronic structure near the Fermi energy during martensitic transformation.

• OSTI ID: 22409941
• Journal Information: Journal of Applied Physics, Vol. 117, Issue 17; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
APPROXIMATIONS
AUSTENITE
CUBIC LATTICES
ELECTRONIC STRUCTURE
ELLIPSOMETRY
FERMI LEVEL
GALLIUM ALLOYS
KERR EFFECT
MAGNETIZATION
MANGANESE ALLOYS
MARTENSITE
MONOCRYSTALS
NICKEL BASE ALLOYS
OPTICAL PROPERTIES
PHASE TRANSFORMATIONS
SHAPE MEMORY EFFECT
TEMPERATURE DEPENDENCE