Unusual magnetic properties of (Er1−xGdx)5Si4 compounds

作     者：Niraj K. Singh V. K. Pecharsky K. A. Gschneidner, Jr. 

作者机构：Materials and Engineering Physics Program Ames Laboratory of United States Department of Energy Iowa State University Ames Iowa 500011-3020 USA and Department of Materials Science and Engineering Iowa State University Ames Iowa 50011-2300 USA 

出 版 物：《Physical Review B》 (Phys. Rev. B Condens. Matter Mater. Phys.)

年 卷 期：2008年第77卷第5期

页      面：054414-054414页

核心收录：

学科分类：0808[工学-电气工程] 0809[工学-电子科学与技术（可授工学、理学学位）] 07[理学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0702[理学-物理学] 

摘      要：Magnetic and magnetocaloric properties of polycrystalline (Er1−xGdx)5Si4 with x=0.1 and 0.25 have been studied. The temperature dependencies of the dc magnetization and ac susceptibility indicate two magnetic transitions: the high temperature transitions are antiferromagnetic in character, whereas the low temperature ones are of ferromagnetic nature. The isothermal magnetization of these compounds shows metamagneticlike transitions at 5K and no saturation in fields up to 70kOe. Time dependencies of the magnetization data below the Néel temperature exhibit unusually strong relaxation effects with logarithmic time dependence. The ac susceptibility data reveal that magnetic state of these compounds is distinctly different from spin glasses and the relaxation behavior seen in the magnetization data is a consequence of complex magnetic interactions. The existence of complex magnetic interactions leads to an easy formation of field induced short range ferromagnetic correlations in the paramagnetic state and greatly affects both the magnetic and magnetocaloric properties of these compounds.