Growth and X-ray characterization of 'Gd IND. x''Yb IND. 1-x' Ta'O IND. 4' (0'< ou ='x'< ou ='1)single crystals with large lattice spacing gradient - Silva, Renato de Almeida; Tirao, G.; Cusatis, C.; Andreeta, José Pedro (Journal of Crystal Growth, 2005)