Structure and properties of nanoporous FePt fabricated by dealloying a melt-spun Fe(60)Pt(20)B(20)alloy and subsequent annealing  

作　　者：Dianguo Ma Yingmin Wang Yanhui Li Rie Y·Umetsu Shuli Ou Kunio Yubuta Wei Zhang 

机构地区：[1]Key Laboratory of Materials Modification by Laser,Ion,and Electron Beams(Ministry of Education),School of Materials Science and Engineering,Dalian University of Technology,Dalian 116024,China Institute for Materials Research,Tohoku University,Sendai 980-8577,Japan

出　　处：《Journal of Materials Science & Technology》2020年第1期128-133,共6页材料科学技术（英文版）

基　　金：supported financially by the National Natural Science Foundation of China(Grant Nos.51571047,51171034);the Fundamental Research Funds for the Central Universities(DUT17ZD212);the Global Institute for Materials Research Tohoku Program,Japan。

摘　　要：A nanoporous FePt alloy has been fabricated by dealloying a melt-spun Fe(60)Pt(20)B(20)alloy composed of nanoscale amorphous and face-centered-cubic FePt(fcc-FePt)phases in H2 SO4 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-Fe Pt into ordered face-centered-tetragonal FePt(L10-FePt)in the nanoporous alloy has been realized after annealing at823-943 K for 600 s.The volume fraction of the L10-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.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 H2 SO4 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-Fe Pt into ordered face-centered-tetragonal FePt（L10-FePt） in the nanoporous alloy has been realized after annealing at823-943 K for 600 s.The volume fraction of the L10-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.

关 键 词：NANOPOROUS metals Fe-Pt-B ALLOY DEALLOYING L10-FePt Magnetic property 

分 类 号：TB383.1[一般工业技术—材料科学与工程]