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采用四亚晶格热力学模型,辅助以第一性原理总能计算,研究了具有ThMn12原型结构的YFe10-xSix金属间化合物中元素的占位有序化行为。结果表明,YFe10.2Si1.8和YFe10Si2化合物中稀土元素Y占据2a亚晶格,Fe占据全部8i亚晶格和部分8j,8f亚晶格,Si占据部分8j,8f亚晶格,且Si更倾向于占据8f亚晶格。随温度的变化,YFe10-xSix化合物中各元素的占位有序化行为并不发生改变。本文预测结果与近期文献报道的实验结果相当吻合,间接证明了成分为YFe10Si2的化合物以ThMn12型结构的YFe10.2Si1.8相和α-(Fe,Si)固溶体相的共存形式更为合理。
The tetragonal lattice thermodynamic model is used to assist in the calculation of the total ordering of the elements in the YFe10-xSix intermetallic compound with the ThMn12 prototypical structure, which can always be calculated by the first principle. The results show that rare earth element Y occupies 2a sub-lattice in YFe10.2Si1.8 and YFe10Si2 compounds, Fe occupies all 8i sub-lattice and some 8j, 8f sub-lattice, and Si occupies part of 8j, 8f sub-lattice, Tend to occupy the 8f sub-lattice. With the change of temperature, the orderly ordering of the elements in YFe10-xSix compounds does not change. The results of this paper are in good agreement with the experimental results recently reported in the literature. It proves that the coexistence of the YFe10.2Si1.8 phase and the α- (Fe, Si) solid phase with ThMn12 structure is more reasonable.