Effects of manganese doping on magnetocaloric effect in Ge-rich Gd_5Ge_(2.05)Si_(1.95) alloy

作     者：E.Yüzüak I.Dincer Y.Elerman 

作者机构：Department of Engineering PhysicsFaculty of EngineeringAnkara University 

出 版 物：《Journal of Rare Earths》 (稀土学报（英文版）)

年 卷 期：2012年第30卷第3期

页      面：217-221页

核心收录：

学科分类：0709[理学-地质学] 0819[工学-矿业工程] 08[工学] 0708[理学-地球物理学] 080502[工学-材料学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0703[理学-化学] 

主　　题：magnetocaloric effect entropy change magnetic materials rare earths 

摘      要：The structure, magnetic and magnetocaloric properties of the Ge-rich Gd5Ge2.05-xSi1.95-xMn2x （x=0.01 and 0.03） alloys were investigated by scanning electron microscopy, X-ray powder diffraction, differential scanning calorimeter （DSC） and magnetization measurements. The results of energy dispersive X-ray analysis （EDX） and X-ray diffraction analyses showed that the composition and crystal structure of the alloys were desired. DSC measurements were performed to determine the transformation temperatures for each alloy. Both alloys exhibited the first order phase transition around room temperature. The alloys showed an anti-ferromagnetic transition around 60 K. The isothermal magnetic entropy changes of the alloys were determined from the isothermal magnetization measurements by using the Maxwell relation. The maximum values of isothermal magnetic entropy change of the Gd5Ge2.05-xSi1.95-xMn2x alloy with x=0.01 was found to be -12.1 and -19.8 J/（kg·K） using Maxwell equation around 268 K in applied fields of 2 and 5 T, respectively.