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论文类型：期刊论文

发表时间：2020-01-01

发表刊物：JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY

收录刊物：EI、SCIE

卷号：36

页面范围：128-133

ISSN号：1005-0302

关键字：Nanoporous metals; Fe-Pt-B alloy; Dealloying; L1(0)-FePt; Magnetic property

摘要：A nanoporous FePt alloy has been fabricated by dealloying a melt-spun Fe60Pt20B20 alloy composed of nanoscale amorphous and face-centered-cubic FePt (fcc-FePt) phases in H2SO4 aqueous solution. The nanoporous alloy consists of single fcc-FePt phase with an Fe/Pt atomic ratio of about 55.3/44.7, and possesses a uniform interpenetrating ligament-channel structure with average ligament and pore sizes of 27 nm and 12 nm, respectively. The nanoporous fcc-FePt alloy shows soft magnetic characteristics with a saturation magnetization of 37.9 emu/g and better electrocatalytic activity for methanol oxidation than commercial Pt/C in acidic environment. The phase transformation from disordered fcc-FePt into ordered face-centered-tetragonal FePt (L1(0)-FePt) in the nanoporous alloy has been realized after annealing at 823-943 K for 600 s. The volume fraction of the L1(0)-FePt phase in the alloy increases with the rise of annealing temperature, which results in the enhancements of coercivity and saturation magnetization from 0.14 kOe and 38.5 emu/g to 8.42 kOe and 51.4 emu/g, respectively. The ligament size of the samples is increased after annealing. (C) 2019 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.