Incorporation of hafnium (IV) into KTP framework from phosphate‐fluoride fluxes

Solid solutions KTi_1‐XHf_XOPO₄ (х = 0.008 – 0.107) possessing the KTiOPO₄ structure, have been synthesized in molten system K₂O‐P₂O₅‐TiO₂‐HfF₄. The crystal growth experiment of Hf‐doped KTP crystal has been reported. The X‐ray powder diffraction data and chemical analysis are also presented. It has been shown that KTiOPO₄ crystal structure slightly changes when Hf incorporates into the framework. Transmission/absorption spectra of KTi_0.974Hf_0.026OPO₄ crystals have been recorded. The incorporation of Hf ions shifts the optical absorption edge in the UV‐visible spectrum towards the long‐wavelength region with absorption near 387 nm.