Exploration of fluorapatite bio-ceramic thin film deposition by ultrasonic spray pyrolysis

Abstract

Spray pyrolysis is utilized for the first time to deposit fluorapatite (FAP) thin films on titanium using different setups and atomizer frequencies. The deposition is explored from solutions of pre-synthesized FAP powder and various chemical precursors at various deposition variables. The crystallinity, texture, and morphology of deposited films are probed using X-ray diffraction and electron microscopy. Smooth and (210) textured films can be successfully deposited from precursors in a single-step process using a 2.4 MHz ultrasonic atomizer in a vertical up configuration and Ca(NO3)2·4H2O, NaF, and Na2HPO4 as precursors. Such precursors give the best crystallinity among the other precursors. Texturing is observed in both basic and acidic solutions for the first time. However, the vertical down-setup with a high-frequency atomizer is more effective for obtaining pure, rough, and (210)-textured FAP film. Additionally, mainly white-colored FAP films are phase pure, while films with other colors are generally composed of mixed phases. Graphical abstract: [Figure not available: see fulltext.]