Crystal structure of La 1−xNd xGaO 3 single crystals (0 < x < 0.2)

Abstract

The structure of La 1−xNd xGaO 3 (x = 0.07, 0.12, 0.17, and 0.20) solid solution single crystals were refined by the Rietveld method using X-ray powder data. All crystals belong to the GdFeO 3 type structure (space group Pbnm, Z = 4). The a and c lattice constants decrease with increasing Nd concentration, whereas the b parameter slightly rises: a = 5.51667(6)–5.50279(8), b = 5.49006(7)–5.49054(8), and c = 7.77003(9)–7.7663(1) Å. Although La–Nd substitution leads to the convergence of perovskite cell constants, only the La 1−xNd xGaO 3 structure dimensionally tends to be cubic. The deformation parameters such as bond-length distortion of polyhedra, degree of octahedra tilts, and distortion of R–R, R–Ga, and Ga–Ga distances, demonstrate an increase of deformation of perovskite structure during La–Nd substitution.