摘要
We present a magnetic force microscopy study of surface magnetic microstructure changes at high temperatures in 2：17-type Sm（Co,Fe, Cu,Zr）z （z ～ 7.4） magnets. Surface magnetic microstructures are found to change greatly in parallel and vertical specimens after heat-treatment at 400℃ for one hour in vacuum of 10^-5 Torr with Ar gas as protecting atmosphere. Changes of microstructures are attributed to the formation of a soft-magnetic surfaces layer in the specimens, resulting from Sm volatilization due to high temperature. This hypothesis is further confirmed by the heat-treatment experiments at 400℃ for 0.5 h and 2 h. Finally, the existence of the soft-magnetic layers, which consist primarily of Fe Co compounds, is verified by the results of both XRD and XPS of the vertical specimens before and after heat-treatment.
We present a magnetic force microscopy study of surface magnetic microstructure changes at high temperatures in 2：17-type Sm（Co,Fe, Cu,Zr）z （z ～ 7.4） magnets. Surface magnetic microstructures are found to change greatly in parallel and vertical specimens after heat-treatment at 400℃ for one hour in vacuum of 10^-5 Torr with Ar gas as protecting atmosphere. Changes of microstructures are attributed to the formation of a soft-magnetic surfaces layer in the specimens, resulting from Sm volatilization due to high temperature. This hypothesis is further confirmed by the heat-treatment experiments at 400℃ for 0.5 h and 2 h. Finally, the existence of the soft-magnetic layers, which consist primarily of Fe Co compounds, is verified by the results of both XRD and XPS of the vertical specimens before and after heat-treatment.
基金
Supported by the National Natural Science Foundation of China under Grant Nos 10374110 and 50201004.
