铽锰基化合物TbMn_6Sn_6的结构和磁性

Structure and Magnetic Properites of TbMn 6Sn 6 Compound

研究了重稀土金属化合物ＴｂＭｎ６Ｓｎ６的晶体结构、内禀磁性及其矫顽力随温度和外场变化的规律。ＴｂＭｎ６Ｓｎ６为ＨｆＦｅ６Ｇｅ６型六角型结构，晶格常数为：ａ＝０５５６１ｎｍ，ｃ＝０９０４７７ｎｍ，单胞体积为０２４１ｎｍ３；居里温度ＴＣ＝４２１Ｋ。ＴｂＭｎ６Ｓｎ６化合物在外场较弱（Ｈｏ＝３２ｋＡ／ｍ）时，热磁曲线呈亚铁磁性；当外场较强时，则表现出铁磁行为，具有变磁性，ＴｂＭｎ６Ｓｎ６的矫顽力随温度变化，当温度Ｔ＝２００Ｋ时，矫顽力为９６０ｋＡ／ｍ，达最大值。

The crystal structure, the intrinsic magnetism and the dependence of coercivity on temperature for TbMn 6Sn 6 were studied in this paper. The TbMn 6Sn 6 compound crystallizes in the HfFe 6Ge 6 type hexagonal structure with the lattice parameter of a =0 5561 nm, c =0 90477 nm. Volume of single unit is 0 241 nm 3 and Curie temperature is T C=421 K. The thermo magnetic curve showed the TbMn 6Sn 6 compound to be ferri magnetism in the low external magnetic field( H o<32 kA/m) and to be ferro magnetism in the relatively high field. The coercivity of the TbMn 6Sn 6 compound has the maximum of 960 kA/m at the temperature T =200 K.