Microstructure and magnetic properties of FeAs with coarse-grain and nanocrystalline structure  

粗晶和纳米晶FeAs的微观结构与磁学性能

作　　者：Yuan ZHOU Yun-yan WANG Yan-jie LIANG Yi-wei ZHOU Zhen-xing LIU Cong PENG Yong KE Xiao-bo MIN 周元;王云燕;梁彦杰;周艺伟;刘振兴;彭聪;柯勇;闵小波(中南大学冶金与环境学院,长沙410083;国家重金属污染防治工程技术研究中心,长沙410083)

机构地区：[1]School of Metallurgy and Environment,Central South University,Changsha 410083,China [2]Chinese National Engineering Research Center for Control&Treatment of Heavy Metal Pollution,Changsha 410083,China

出　　处：《Transactions of Nonferrous Metals Society of China》2022年第3期972-979,共8页中国有色金属学报（英文版）

基　　金：the financial support from National Key Technologies R&D Program of China (No. 2018YFC1900302)。

摘　　要：The microstructure and magnetic properties of iron arsenide(FeAs) with coarse-grain and nanocrystalline structure were investigated. Coarse-grain FeAs was synthesized through high-energy ball milling and heat treatment. Nanocrystalline FeAs was obtained by ball milling of coarse-grain FeAs. The results suggest that the reduced grain size of FeAs(from >100 to 32.4 nm) is accompanied by the introduction of internal strains up to 0.568% with ball milling time from 0 to 32 h. The magnetic properties of FeAs show that the coercivity is reduced from 29.2 to 15.6 kA/m and the magnetization is increased over time of milling. The low coercivity is mainly due to the small grain size stemmed from ball milling, while the increase of magnetization is primarily caused by the change of lattice parameters of FeAs and the emergence of superparamagnetic phase at the same time.研究粗晶及纳米晶FeAs的微观结构和磁学性能。首先通过高能球磨和热处理制备粗晶FeAs,随后将粗晶FeAs进行不同时间球磨得到纳米晶FeAs。结果表明,球磨时间为32h时,平均晶粒尺寸由>100nm减小到32.4 nm,同时内应变增加到0.568%。随着球磨时间的增加,矫顽力由球磨前的29.2 kA/m降低到15.6 kA/m,同时磁化强度提高。分析认为,晶粒尺寸的减小导致FeAs矫顽力的降低,而球磨过程中晶胞参数的变化和超顺磁相的出现则导致磁化强度的提高。

关 键 词：high-energy ball milling iron arsenide COERCIVITY MAGNETIZATION 

分 类 号：TQ138.11[化学工程—无机化工]