D. J. Green—contributing editor
Theoretical Defect Energetics in Calcium Phosphate Bioceramics
Article first published online: 21 DEC 2009
© 2009 The American Ceramic Society
Journal of the American Ceramic Society
Volume 93, Issue 1, pages 1–14, January 2010
How to Cite
Matsunaga, K. (2010), Theoretical Defect Energetics in Calcium Phosphate Bioceramics. Journal of the American Ceramic Society, 93: 1–14. doi: 10.1111/j.1551-2916.2009.03485.x
- Issue published online: 21 DEC 2009
- Article first published online: 21 DEC 2009
- Manuscript No. 26631. Received July 31, 2009; approved October 5, 2009.
Vacancies, impurities, and foreign ions dissolving in calcium phosphate bioceramics play an important role in the biological properties of the materials. However, little is known about the thermodynamic stability of the defects. In this regard, point defects in hydroxyapatite (HAp) and octacalcium phosphate (OCP) were calculated in a first-principles manner, and the chemical-potential dependence of the defect formation energies was revealed. In particular, because calcium phosphates are usually subjected to an aqueous solution, a methodology to evaluate ionic chemical potentials under chemical equilibrium of the solid–aqueous solution was introduced. In the present article, recent results based on such a methodology (the solution pH dependence of Ca/P molar ratio of HAp and the ion-exchange ability with foreign cations in HAp and OCP) were reviewed.