Magnetostrictive Properties of Galfenol Alloys Under Compressive Stress

NanodispersedDO3-phase nanostructures observed in magnetostrictive Fe–19% Ga Galfenol alloys

“…For Fe-22% Ga, these DO 3 regions coarsened to sizes of Ͼ400 nm upon thermal annealing at temperatures slightly below the A2-DO 3 boundary. The size of our nanoregions for x = 19 at % Ga are smaller than those of Ikeda et al; 5 however, they are of similar size as those previously reported in Fe-Al alloys in the K field, 17,18 and to that of McQueeny et al 21 by synchrotron radiation for Fe-19% Ga. Furthermore, ongoing investigations by our research team have shown similar coarsening-resistant nanodispersions of DO 3 in an A 2 matrix for 10Ͻ x Ͻ 20 at %, which will be published at a later date after more thorough studies are completed.…”

“…The Fe-19% Ga alloy, used in present study, was grown at Ames Laboratory using the Bridgman method as described by Clark et al 17 This sample was further annealed for 3 days at 550°C to reduce stress introduced during growth by rapid furnace cooling ͑10°C / min͒.…”

Magnetic force microscopy investigation of domain structures in Fe–xat.% Ga single crystals (12<x<25)

“…9 The crystals were annealed at 1000°C for 168 h, with heating and cooling rates of 10°/ min, after which the crystals were considered to be in the FC state. The ͑001͒-oriented 10ϫ 10-mm 2 faces were polished down to 0.25-m finish.…”

Neutron diffraction studies of magnetostrictive Fe–Ga alloy ribbons

“…1 However, appreciable amounts of Ga well in excess of the solubility limit can be retained in the metastable disordered bcc solid solution phase ͑A2 phase͒ at room temperature by rapid cooling. [1][2][3] The replacement of Fe by Ga results in a large increase in magnetostriction, approaching 400 ppm for quenched single crystals [4][5][6] at room temperature, with low saturation fields of several hundreds of oersted, and over −2000 ppm has been reported for melt-spun Fe-Ga ribbons. 7,8 The magnetostriction 100 maximizes around 17-19 at.…”