Effects of Mg doping on sol-gel derived nanocrystalline hydroxyapatite thin films

Abstract

Both pure and Mg doped thin films were fabricated by sol-gel dip coating. The films were sintered either at 800 or 1000 degrees C. The average grain size of the films was significantly affected by Mg substitution in the hydroxyapatite (HA) structure and change in the sintering temperature. The grains were considerably larger in the films sintered at higher temperatures. In addition, Mg doped films contained significantly larger grains compared to undoped HA films. Mg doping also caused rodlike grains at 800 degrees C, and led to whitlockite (beta-TCP) formation at 1000 degrees C. The ratio of the existing phases was estimated as beta-TCP/HA = 27:73. All the films had rough surfaces with high porosity. It was also observed that undoped films had higher surface roughness than Mg doped ones.