Dilute magnetism and vibrational entropy in Fe2Al5

作     者：Ji Chi Xiang Zheng Sergio Y. Rodriguez Yang Li Weiping Gou V. Goruganti K. D. D. Rathnayaka Joseph H. Ross, Jr. 

作者机构：Department of Physics Texas A&M University College Station Texas 77843-4242 USA Materials Science and Engineering Program Texas A&M University College Station Texas 77843-3003 USA Department of Engineering Science and Materials University of Puerto Rico at Mayaguez Mayaguez Puerto Rico 00681-9044 USA 

出 版 物：《Physical Review B》 (物理学评论B辑：凝聚态物质与材料物理学)

年 卷 期：2010年第82卷第17期

页      面：174419-174419页

核心收录：

学科分类：07[理学] 0702[理学-物理学] 

基　　金：Directorate for Mathematical and Physical Sciences  MPS  (0315476) 

摘      要：Fe2Al5 contains a Fe-Al matrix through which are threaded disordered one-dimensional chains of overlapping Al sites. We report magnetic, nuclear-magnetic-resonance (NMR), and specific-heat measurements addressing its magnetic and vibrational properties. The Curie-type susceptibility is found to be due to dilute moments, likely due to wrong-site Fe atoms. A27l NMR shift and spin-lattice relaxation measurements confirm these to be indirectly coupled through a Ruderman-Kittel-Kasuya-Yoshida-type interaction. Specific-heat results indicate a large density of low-energy vibrational modes. These excitations generate a linear-T contribution to the specific heat, which however freezes out below about 10 K. These results are attributed to the presence of anharmonic vibrational modes associated with the disordered structural chains.