| 摘要 |
PROBLEM TO BE SOLVED: To provide a rare earth polyboride containing silicon which is useful for a highly functional material e.g. a material for a thermoelectric element, a spectroscopic device material, and a luminescent material. SOLUTION: There is provided the rare earth borosilicide which is expressed by the chemical formula: RE1-x B12 Si4-y (wherein, RE is one or >=2 rare earth elements selected from among Y, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu, and the range of x and y is 0<=x<=0.7, 0<=y<=2) and its crystal structure is rhombohedral system (space group R-3m). Each RE-B-Si compound has the lattice constants of 1, b=1.005 to 1.009 nm, c=1.630 to 1.647 nm, which are little depending on the kinds of elements, and compositions of rare earth elements. The compound of definite ratio composition of x, y=0 is REB12 Si4 , but the most stable compound is composed of each of x and y is about 0.3 and 0.8 respectively, and its chemical composition corresponds REB17.2 Si4.6 .
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