Thermo-physical insights into a series of strontium substituted hydroxyapatite

• Published in: Materials chemistry and physics 2021-01, Vol.258, p.123910, Article 123910
• Main Authors: Erdem Bastan, Fatih, Ur Rehman, Muhammad Atiq, Ustel, Fatih
• Format: Article
• Language: English
• Subjects: Crystal lattices; Decomposition; DTA; DTG; Heat treatment; Hydroxyapatite; Lattice parameters; Physical properties; Raman spectroscopy; Rietveld refinement; Substitutes; Thermal stability
• ISSN: 0254-0584; 1879-3312
• DOI: 10.1016/j.matchemphys.2020.123910

In this study, we investigated the effect of Sr substitution (2, 4, 8, 16 mol. %) on the thermo-physical properties of hydroxyapatite (HA). FTIR and Raman analysis revealed that Sr substitution incorporated CO32− and HPO42− into the HA lattice and consequently SrHA lost more mass according to the TG studies. The substitution of Sr reduced the dehydroxylation peak temperatures from 1266 °C to 1226 °C and decomposition peak temperatures from 1472 °C to 1432 °C. Heat treated HA, 2SrHA, 4SrHA and 8SrHA preserved dominant HA phase (>99%). However, 16SrHA decomposed to TCP (>23 wt %). Moreover, Sr substitution increased the “a” and “c” lattice constants and thus, enlarging the crystal volume of HA. Raman studies confirmed that Sr substituted HAs up to 8 mol % decomposed slightly to oxyhydroxyapatite (OHA). We employed a deconvolution process to the Raman peaks at ~960 cm−1 to calculate the degree of the OHA decomposition by Sr substitution. •The effects of Sr doping on the thermo-physical properties of HA were investigated.•Sr substitution incorporated CO32− and HPO42− into the HA lattice.•Sr doping reduced the dehydroxylation and decomposition peak temperatures.•Sr increased the lattice constants and enlarge the crystal volume of HA.•The decomposition of HA was calculated by the Raman peak deconvolution.