无序化对有序铁铝金属间化合物磁性的影响  

Influence of Disordering on the Magnetic Properties of Ordered Iron Aluminides

作　　者：范润华[1] 尹文宗[1] 孙康宁[1] 孙家涛[1] 张玉军[1] 

机构地区：[1]山东大学材料液态结构及其遗传性教育部重点实验室,济南250061

出　　处：《人工晶体学报》2005年第4期606-609,共4页Journal of Synthetic Crystals

基　　金：国家自然科学基金(No.50242008)资助项目

摘　　要：在平衡态时,化学计量比成份Fe3Al具有D03超结构,并表现出铁磁性,平均每个Fe原子的磁矩是1.7μB,而具有B2超结构的FeAl却是无磁的。利用快速凝固、冷加工处理、溅射和械合金化等非平衡加工技术可以使D03-Fe3Al和B2-FeAl等有序铁铝金属间化合物相无序化。本文利用固体与分子经验电子理论(EET)和Jaccarino-Walker模型对铁铝金属间化合物的磁性进行了计算,研究了无序化对Fe-Al有序相磁性的影响。结果表明:完全无序的Fe75Al25和Fe50Al50,每个Fe原子的平均磁矩分别是2.01μB、1.41μB,铁铝金属间化合物的磁性可以通过无序化提高。Iron aluminides display a wide range of mechanical, electronic, transport, and magnetic properties. While the disordered Fe-Al solid solutions are ferromagnetic in the concentration range 0-22 at. % Al, DO3-ordered F% Al is also ferromagnetic and has the magnetic moment of 2.2μB and 1.45μB for two different Fe sites, with average magnetic moment per Fe atom 1.7μB ; and B2-ordered FeAl is nonmagnetic. However, iron aluminides could be disordered through non-equilibrium technique, such as sputtering, co-evaporation, mechanical alloying, rapid solidification, or cold-working treatment through rolling or crushing. Many researchers have found that the solid solubility limit of A1 in the disordered FeAl solid solutions could be extend up to 50 at. %. In this paper, the magnetic properties of disordered FeAl,DO3-F%Al and B2-FeAl are studied by the empirical electron theory of solid and molecular （EET） and Jaccarino-Walker model. The results indicate that the average magnetic moment per Fe atom is 2.01μB and 1.41μB for the complete disordered Fe75A125 and Fe50Al50, respectively, which are larger evidently than the ordered states.

关 键 词：磁性能 铁铝金属间化合物 有序-无序 固体与分子经验电子理论 Jaccarino-Walker模型 

分 类 号：O612[理学—无机化学]