The solid solutions TbCuIn_1–x M _x (M = Al, Ga)

Abstract

The complete solid solutions TbCuIn1–x M x (M = Al, Ga) were studied by powder X-ray diffraction and scanning electron microscopy for samples equilibrated at T = 873 K. The influence of In substitution by Al or Ga, the solubility ranges and the changes of unit cell parameters have been determined: TbCuIn1.0–0Al0–1.0 (ZrNiAl type, space group P 6 ‾ 2 $\overline{6}2$ m, a = 0.7457(1)–0.7035(1), c = 0.3958(1)–0.4044(1) nm, V = 0.1906–0.1733 nm3); TbCuIn1–0.8Ga0–0.2 (ZrNiAl type, a = 0.74569(5)–0.73882(13), с = 0.39582(3)–0.39663(14) nm, V = 0.1906–0.1875 nm3); TbCuIn0.3–0Ga0.7–1.0 (KHg2 type, Imma, а = 0.43943(9)–0.43750(5), b = 0.70833(12)–0.70537(6), с = 0.74866(12)–0.74525(7) nm, V = 0.2330–0.2300 nm3). The crystal structure of TbCuIn0.42(1)Al0.58(1) was refined from single-crystal X-ray diffractometer data: ZrNiAl type, P 6 ‾ 2 $\overline{6}2$ m, a = 0.71633(6), c = 0.40785(3) nm, wR2 = 0.0379, 291 F 2 values and 16 variables. The basic crystal chemical features are discussed.