Electrical, optical, and structural properties of tin-doped In₂O₃-M₂O₃ solid solutions (M = Y, Sc)

In₂O₃ crystallizes in the bixbyite, or C-type rare earth, structure (space group Ia3), as do the smaller lanthanide oxides (Tb-Lu) and the oxides of Y and Sc. Solid solutions of In(2-x)M(x)O(3-δ) (M = Y or Sc) with varying lattice parameters were prepared and doped with tin. Substitution of tin oxide into In(2-x)Y(x)O(3-δ) results in the formation of the pyrochlore phase, Y₂Sn₂O₇. The pyrochlore dominates the Y-In-Sn oxide ternary phase diagram and prevents the tin from donating charge carriers. Solid solutions in which M = Sc could be reacted with a limited amount of tin oxide without the formation of a second phase. The presence of increasing scandium results in decreasing conductivity with a corresponding increase in the optical band gap and percent transmission. (C) 2000 Academic Press.