Effect of gadolinium (Gd3+) addition on the monophased field and crystal growth of Ba2NaNb5O15 (BNN)

Ba2Na1-3xGdxNb5O15 compounds with (0.02 less than or equal tox less than or equal to0.2) have been prepared. The limit of the monophased composition f ield was determined as a function of Gd substitution. The effect of Gd on b arium sodium niobate (BNN) was examined by X-ray powder diffraction at room temperature as a function of temperature. The melt behavior was studied by DTA. The homogeneity of single-crystal fibers doped with Gd and grown by m icro-pulling down technique was investigated by EPMA. No cracks or other in homogeneities could be detected, as already shown for Yb- and Nd-doped BNN. In this study, Gd addition was effective for growth of bulk crystals by Cz ochralski technique. (C) 2001 Elsevier Science B.V. All rights reserved.