Flux Growth and External Morphology of KTiOPO₄ Crystals

Abstract

KTiOPO 4 (KTP) crystals with high quality and weight exceeding 230 g have been obtained on seeds from high-temperature solutions based on the K 6 P 4 O 13 (K6) flux. The next priority was the flux crystallization of KTP material in the presence of M 2 SO 4 -type mineralizers ( M = Li, Na, K). The motivation of the work was to find the effect of flux composition on KTP morphology by an addition of alkali sulfates on the scheme: K6: M 2 SO 4 = 8, 6, and 4. Small spontaneous KTP crystals were also obtained from the fluxed melts doped with V, Cr, Ni, Co, Cu, Mo, Ba, Ce, Er, and W under similar conditions. Chromium admixture in solid phase was measured to be up to 0.5 wt %. Other dopants were less than 0.02 wt %. In all experiments, typical faceting of KTP crystals is {100}, {011}, and {201}. In the case of vanadium, the {111} faces are formed, additionally to the above crystal forms. In the presence of the Li 2 SO 4 mineralizer, {111} and {031} faces were found as well.