磁制冷材料Gd_5Ge_4中的磁玻璃态(英文)  

The magnetic glass state in the magnetocaloric material Gd_5Ge_4

作　　者：董彤[1] 袁淑娟[1,2] 葛军饴[1] 洪芳[1] 郁黎明[1] 曹世勋[1] 张金仓[1] 

机构地区：[1]上海大学物理系,上海200444 [2]南京大学固体微结构实验室,南京210093

出　　处：《山东大学学报（工学版）》2009年第3期67-70,93,共5页Journal of Shandong University（Engineering Science）

基　　金：National Natural Science Foundationof China(10504019,10674092);Shanghai Nano-technology Promotion Center and the Science & Technology Committee of Shanghai Municipality(0652nm046).

摘　　要：Gd5Ge4低温时具有玻璃态的不稳定性,与钴氧化物La0.88Sr0.12CoO3的冻结的自旋玻璃态不同.通过分别研究经过零场冷过程后Gd5Ge4和La0.88Sr0.12CoO3在低温区域的温度循环对磁化强度的影响,发现在Gd5Ge4样品中磁化强度随着温度循环的增加而不断增大,但是在La0.88Sr0.12CoO3样品中温度循环对其磁化强度几乎没有影响.Gd5Ge4和La0.88Sr0.12CoO3的直流磁化强度和交流磁化率也进行了测量.Gd5Ge4的交流磁化率的峰并不随着频率的增加而向高温区移动,这个现象不同于La0.88Sr0.12CoO3样品的.通过不同物理参数的测量,证明了Gd5Ge4的这种磁玻璃态不同于传统的自旋玻璃态.The metastable property of glasslike dynamics at low temperature of Gd5 Ge4 was presented in contrast to the stable frozen spin glass state in cobalfite La0.88 Sr0.12 CoO3 （LSCO）. Through investigating the effect of temperature cycle on magnetization at the low temperature region after the zero field cooled procedure of Gd5 Ge4 and La0.88 Sr0.12 CoO3 respectively, it was found that the magnetization continues to increase with increasing the temperature cycle in Gd5 Ge4, while there was hardly any effect on magnetization in La0.88Sr0.12 CoO3 The dc magnetization and ac susceptibility were also measured on Gd5Ge4 and La0.88 Sr0.12 CoO3. The peaks of ac susceptibility in Gd5 Ge4 did not move to the higher temperature region with increasing frequency, which were different from the phenomena of La0.88 Sr0.12 CoO3. This kind of magnetic glass state in Gd5 Ge4 is quite different h-om conventional spin glass.

关 键 词：磁制冷材料 Gd5Ge4 磁玻璃态 磁热材料 

分 类 号：O482[理学—固体物理] TM2[理学—物理]