Chinese Physics, 2003, Vol. 12(11): 1305-1309    DOI: 10.1088/1009-1963/12/11/321
 CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES Prev   Next

# Domain structures of Nd13Fe80B7 magnets during HDDR process

Zhang Zhen-Rong (张臻蓉)a, Pang Zhi-Yong (庞智勇)b, Zhao Yi-Min (赵义敏)c, Zhang Zheng-Yi (张正义)c, Han Sheng-Hao (韩圣浩)b, Han Bao-Shan (韩宝善)a
a  State Key Laboratory of Magnetism, Institute of Physics, and Center of Condensed Matter Physics, Chinese Academy of Sciences, Beijing 100080, China; b School of Physics and Microelectronics, State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China; c Institute of Materials, University of Science and Technology Beijing, Beijing 100083, China
Abstract  The domain structures of Nd$_{13}$Fe$_{80}$B$_7$ alloy at different stages of the HDDR process have been revealed using a magnetic force microscope. In the as-cast samples, the columnar crystals with easy axis perpendicular to one another are clearly characterized by their different domain structures. For the insufficient and sufficient HD treatment, an obvious change of domain structure occurs, which is related to the variation of composition and crystalline microstructure during the HD process. And for the samples after sufficient DR processing, it is confirmed that the configuration of the columnar crystals is retained by the detected domain structures.
Keywords:  magnetic domain structure      Nd-Fe-B      HDDR      magnetic force microscope (MFM)
Received:  20 May 2003      Revised:  08 August 2003      Accepted manuscript online:
 PACS: 75.60.Ch (Domain walls and domain structure) 75.50.Bb (Fe and its alloys) 81.40.-z (Treatment of materials and its effects on microstructure, nanostructure, And properties)
Fund: Project supported by the National Natural Science Foundation of China (Grant No 10074081) and by the National Key Basic Research and Development Programme of China (Grant No 2001CB610504).