Microstructure, Orientation, and Properties of Sol‐Gel‐Derived KTiOPO₄ Thin Films

Dense and crack‐free thin films of potassium titanyl phosphate (KTP) were synthesized using a sol‐gel process. The decomposition of the organic precursors and the formation of the KTP were studied using thermal analysis, DRIFT, and XRD. Several processing parameters such as the nature of the precursors, the aging of the alkoxide solution, the firing atmosphere, time, and temperature were found to affect the final film microstructure. Thin films were deposited on single‐crystal KTP, LaGaO₃, MgO, and sapphire substrates to promote crystallographic orientation. SEM and XRD studies reveal that films deposited on KTP and LaGaO₃ single crystals are highly oriented. The films deposited on MgO or sapphire were found to detach or chemically degrade. The orientation as well as the degradation mechanisms were examined in detail.