Growth striations, growth sector boundaries and grown-in dislocations in flux-grown Nb-doped crystals, K1-xNbxTi1-xOPO4 (where x ranged from 0.02 to 0.125), were investigated by means of white-beam synchrotron radiation topography. The distribution of growth sectors, which consisted mainly of {011} and {201} sectors, was characterized, and the effects of growth striations upon non-critical phase-matching along the [100] direction were considered. The existence of growth striations of {201} and {011} growth sectors, especially those of the {011} sector, were expected to be detrimental in applications of bulk crystals. It was concluded that the Nb-doping of this material could produce electrical self-compensation via the creation of K vacancies. The incorporation of large Nb atoms at octahedral - mainly Ti[1] - sites, and the loss of K atoms from cage sites, affected the crystal structure of Nb-doped samples.

W.J.Liu, S.S.Jiang, X.R.Huang, X.B.Huang, X.B.Hu, W.Zeng, J.Q.Wei, J.H.Wang, J.H.Jiang, Y.Han: Journal of Crystal Growth, 1996, 169[3], 534-8