Structure and atomic displacement in micro-pulling down crystals of potassium lithium niobate

To reveal the effects of compositional changes in the structure of potassium lithium niobate (K₃Li_2-xNb_5+xO₁₅) grown by the micro-pulling down (μ-PD) method, the structure and polar atomic displacements of the metal atoms were studied by X-ray analysis. The polar components of the atomic displacement of the metal atoms Nb(1) and Nb(2) was determined to be 0.193 and 0.186 , 0.162 and 0.154 , and 0.115 and 0.114 for melt compositions of x=-0.3, 0, and +0.3, respectively. It was shown that the displacements of the Nb sites increased as the Nb content decreased.