Growth and X-ray characterization of GdxYb1−xTaO4 (0⩽x⩽1) single crystals with large lattice spacing gradient

Gradient single crystal fibers of GdTaO4-YbTaO4 have been grown by laser-heated pedestal growth (LHPG). The crystals of the compounds have differences in the lattice parameters of Δa/aav=2.5%, Δb/bav=2.2% and Δc/cav=0.9%. The crystals obtained exhibit an optimum linear distribution of the compounds along the fiber axis and a lattice spacing gradient value of 2.91%/cm for (64¯0) reflection, the largest value of lattice spacing gradient reported up to this moment. The compositional and structural analysis shows that the LHPG technique and the GdTaO4-YbTaO4 system are very promising for obtaining good quality gradient crystals with large lattice parameters gradient.