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Indexed by:Journal Papers

Date of Publication:2009-03-01

Journal:JOURNAL OF APPLIED PHYSICS

Included Journals:SCIE、EI

Volume:105

Issue:5

ISSN No.:0021-8979

Key Words:amorphous magnetic materials; annealing; boron alloys; cobalt alloys; coercive force; differential scanning calorimetry; ferromagnetic materials; fracture toughness; gadolinium alloys; glass structure; glass transition; iron alloys; metallic glasses; niobium alloys; soft magnetic materials; thermal stability; transmission electron microscopy; vitrification; X-ray diffraction

Abstract:The structure, thermal stability, and crystalline behavior of (Fe(0.9)Co(0.1))(67.5)Nb(4)Gd(3.5)B(25) glassy alloy, which exhibits a two-stage-like glass transition phenomenon, were investigated using x-ray diffraction, transmission electron microscopy, and differential scanning calorimetry. The nanoscale metastable (Fe,Co)(23)B(6) phase precipitated in the glassy matrix after annealing, while the two-stage-like glass transition disappeared, indicating the two-stage-like glass transition results from the overlap of the endothermic reaction for the glass transition with the exothermic reaction for the formation of the (Fe,Co)(23)B(6) phase in the supercooled liquid region. The (Fe(0.9)Co(0.1))(67.5)Nb(4)Gd(3.5)B(25) glassy alloy exhibits high glass-forming ability, enabling the formation of glassy alloy rods with diameters exceeding 3.0 mm, rather high saturation magnetization of 0.91 T, low coercive force of 2.5 A/m, and high fracture strength of 3870 MPa.