The role of texturing and densification on optical transmittance of hydroxyapatite ceramics

A high level of optical transparency (over 65%) has been obtained in hydroxyapatite ceramics. This optical transparency arises due to a combination of the texture, measured as the extent of an in-plane orientation of the crystallographic c-axis, and the physical density. The highest value of transparency is observed in pellets sintered at 900°C, below which the transmittance declines due to a decline in the density and texture. Above 900°C, the transmittance declines again due to a loss in the c-axis orientation.