Structural and magnetic characterization of martensitic Ni–Mn–Ga thin films deposited on Mo foil

• Published in: Acta materialia Vol. 54; no. 20; pp. 5461 - 5467
• Main Authors: Chernenko, V.A., Anton, R. Lopez, Kohl, M., Barandiaran, J.M., Ohtsuka, M., Orue, I., Besseghini, S.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.12.2006; Elsevier Science
• Subjects: Applied sciences; Deposition; Exact sciences and technology; Ferromagnetic shape memory alloys; Film thickness; Foils (structural shapes); Magnetic domains; Magnetic fields; Magnetostrain; Metals. Metallurgy; Nickel; Thin films; Thin films; Magnetic domains; Magnetostrain; Ferromagnetic shape memory alloys; Shape memory alloy; Magnetic domain; Thin sheet; Thin film
• ISSN: 1359-6454; 1873-2453
• DOI: 10.1016/j.actamat.2006.06.058

Three martensitic Ni 51.4Mn 28.3Ga 20.3 thin films sputter-deposited on a Mo foil were investigated with regard to their crystal and magnetic domain structures, as well as their magnetic and magnetostrain properties. The film thicknesses, d, were 0.1, 0.4 and 1.0μm. X-ray and electron diffraction patterns revealed a tetragonal modulated martensitic phase (10 M) in the films. The surface topography and micromagnetic structure were studied by scanning probe microscopy. A maze magnetic domain structure featuring a large out-of-plane magnetization component was found in all films. The domain width, δ, depends on the film thickness as δ ∼ d . The thickness dependencies of the saturation magnetization, saturation magnetic field and magnetic anisotropy were clarified. Beam cantilever tests on the Ni–Mn–Ga/Mo composite as a function of magnetic field showed reversible strains, which are larger than ordinary magnetostriction.