Polarisation Behaviour of Calcium Phosphate Based Ceramics
This paper studies the effects of porosity, sintering atmosphere and composition on the polarisation behaviour of calcium phosphate (CaP) ceramics. Hydroxyapatite (HA) and α- tricalcium phosphate (α-TCP) materials were prepared as both dense discs and as porous samples with interconnecting porosity. Materials were sintered in either air or water vapour at 1300°C and poled at a variety of temperatures, applied electric fields and time periods to optimise the polarisation properties of the materials. Thermally Stimulated Depolarisation Current (TSDC) measurements were used to investigate the degree of polarisation of the HA and α-TCP ceramics. A high depolarisation current was observed for both the porous HA and α-TCP ceramics. Sintering in water vapour also increased the depolarisation current due to reduced dehydration reactions, which result in a greater concentration of hydroxyl ions.
António Torres Marques, António Fernando Silva, António Paulo Monteiro Baptista, Carlos Sá, Fernando Jorge Lino Alves, Luís Filipe Malheiros and Manuel Vieira
J.P. Gittings et al., "Polarisation Behaviour of Calcium Phosphate Based Ceramics", Materials Science Forum, Vols. 587-588, pp. 91-95, 2008