Abnormal magnetization behaviors in Sm-Ni-Fe-Cu alloys

作者：Yang, W. Y.; Zhang, Y. F.; Zhao, H.; Chen, G. F.; Zhang, Y.; Du, H. L.; Liu, S. Q.; Wang, C. S.; Han, J. Z.; Yang, Y. C.; Yang, J. B.^*

来源：Journal of Magnetism and Magnetic Materials, 2016, 407: 224-229.

DOI：10.1016/j.jmmm.2016.01.042

• Magnetization mechanism
• Step-like magnetization
• Thermal activation magnetization

The magnetization behaviors in Sm-Ni-Fe-Cu alloys at low temperatures have been investigated. It was found that the hysteresis loops show wasp-waisted character at low temperatures, which has been proved to be related to the existence of multi -phases, the Fe/Ni soft magnetic phases and the CaCus-type hard magnetic phase. A smooth -jump behavior of the magnetization is observed at T> 5 K, whereas a step -like magnetization process appears at T < 5 K. The CaCus-type phase is responsible for such abnormal magnetization behavior. The magnetic moment reversal model with thermal activation is used to explain the relation of the critical magnetic field (H-cm) to the temperature (T> 5 K). The reversal of the moment direction has to cross over an energy barrier of about 6.6 x 10(-15) erg. The step -like jumps of the magnetization below 5 K is proposed to be resulted from a sharp increase of the sample temperature under the heat released by the irreversible domain wall motion.

• 出版日期2016-6-1
• 单位北京大学