Tb2O3: Synthesis, Single Crystal X-Ray Diffraction Analysis, Thermal Expansion in the Range of 90-490 K

Fine crystal samples of terbium oxide C-Tb₂O₃ (space group \(Ia\bar{3}\), Z = 16) are grown from the solution-melt, which are differently colored - colorless and pale brown. No significant differences are revealed by the single crystal X-ray diffraction analysis. The unit cell parameters are refined using the external standard at T = 300 K with relative error Δa/a = 2·10^–5. Values a = 10.7302(2) Å and 10.7296(2) Å are obtained for the colorless sample and the pale brown one respectively. Dependence a(T) is studied in the range of 90-490 K for the colorless crystal. Experimental points are described by the polynomial: a = 10.716 + 2.7· ·10^–5T + 7.2·10^–8T².