title: Stress-assisted large magnetic-field-induced strain in single-variant Co-Ni-Ga ferromagnetic shape memory alloy.
abstract: The magnetic anisotropy and the magnetic-field-induced strain (MFIS) in a single-variant Co(47.5)Ni(22.5)Ga(30.0) ferromagnetic shape memory alloy (FSMA) have been investigated. From the magnetization curves for the single crystal, the hard c-axis was confirmed, and the uniaxial magnetic anisotropy constant K(u) at 300 K was evaluated to be -1.07 × 10(6) erg cm(-3) for the single-variant Co(47.5)Ni(22.5)Ga(30.0) martensite phase. The magnitude of compressive shear stress for the variant rearrangement was estimated to be 6.0-7.5 MPa from the stress-strain curves. An assisted stress τ(assist) of 6.0 MPa was applied before applying a magnetic field, and then a magnetic stress τ(mag) of 0.3 MPa was added. As a result, a large MFIS of about 7.6 % was obtained at room temperature in the martensite phase of the single-variant Co(47.5)Ni(22.5)Ga(30.0).
authors.affiliation: Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Katahira 2-1-1, Sendai 980-8577, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Morito
authors.forename: K
authors.initials: K
authors.lastname: Oikawa
authors.forename: A
authors.initials: A
authors.lastname: Fujita
authors.forename: K
authors.initials: K
authors.lastname: Fukamichi
authors.forename: R
authors.initials: R
authors.lastname: Kainuma
authors.forename: K
authors.initials: K
authors.lastname: Ishida