【作者】 顾正飞； 刘正义； 梁思祖； F.R.de Boer； K.H.J.Buschow；

【Author】 GU Zheng-fei, LIU Zheng-yi, LIANG Si-zu, ZENG De-chang, F.R. de Boer, K.H.J. Buschow Guilin Univercity of Electronic Technology, Guilin 541004, China) South China University of Technology, Guangzhou 510640, China Van der Waals-Zeeman Institute, University of Amsterdam, The Netherlands

【机构】 桂林电子工业学院 信息材料科学与工程系； 华南理工大学 机械工程学院； Van der Waals-Zeeman Institute University of Amsterdam Amsterdam,The Netherlands；

【摘要】 采用X射线衍射、金相观察、电子探针、透射电镜和磁性测量研究了Gd2Co17-xAlx(x≤5)合金的微结构、相组成、相成分和热磁特性。结果表明,在1173K和1323K退火的x≤3的样品和在1323K 退火的x=4的样品近似为单相,主相2:17相仅含Gd、Co、Al三种元素,具有菱方Th2Zn17型结构, 少量杂质相是富Gd氧化物、富Co相或ζ-CoAl相:在1173K退火的x=4的样品含有较多的第二相, 它是具有六方CaCu5型结构的1:5相;x=5的退火样品是三相,主相是1:5相,第二相和第三相分别是2:17相和具有CsCl结构的ζ-CoAl相,提高退火温度,样品的2:17相含量增多,1:5相相应减少:在室温以下,样品(x≤4)的自发磁化强度随温度降低而减小,在74K和65K附近,x=4的两相样品和单相样品的自发磁化强度Mo先后降为零,但x=5的样品磁距随温度降低而增大。更多还原

【Abstract】 The microstructure, phase constituent and compositions and thermal magnetic behavior of Gd2Co17-xAlx ( x≤5 ) alloys have been studied by means of the X-ray diffraction, metallographic examination, electron probe microanalysis and transmission electron microscopy. Results show that the samples with jc < 3 annealed at 1173 K and 1323K and the sample with x = 4 annealed at 1323 K are approximately single phase, 2:17 main phase with rhombohedral Th2Zn17-type structure only containing Gd, Co and Al elements,, while the small amount of impurity phases being the oxide of rich-Gd, Co-rich phase or ζ -CoAl. The sample with x = 4 annealed at 1173 K has quite a lot of the 1 :5 second phase with CaCu5-type structure. The sample with x = 5, as expected, is three-phase, and its main phase is 1 I 5 and the second and third phase are 2:17 phase and ζ -CoAl with CsCl -type structure, respectively. Increasing annealing-temperature is in favour of the formation of 2:17 phase and the reduction of the 1:5 phase. Below the room-temperature, the spontaneous magnetization of annealed samples (x≤4) reduces with decreasing the temperature. The value of Mo reduces to zero at about 74K和 65K, respectively, for the double-phase and single-phase samples with x = 4. But the moment of the annealed sample with x = 5 increases as decreasing the temperature.更多还原