Structural and thermal characterization of SiO2–P2O5 sol–gel powders upon annealing at high temperatures

Low-temperature crystallization and high-temperature instability of hydroxyapatite thin films deposited on Ru, Ti, and Pt metal substrates

“…The loss of PO x itself in the deposition process is more realistic, and the remaining CaO will build up at grain boundaries [29]. Since no precipitation of CaO was observed for HAp films deposited on Si under the same sputtering conditions [41], the precipitation of CaO when using SiO 2 indicates that PO x partially diffused into SiO 2 and formed P 2 O 5 -SiO 2 compounds such as SiP 2 O 7 and Si 3 (PO 4 ) 4 [44][45][46][47]. Fig.…”

Investigations on sol–gel process and structural characterization of SiO2-P2O5 powders

“…Tian et al [26,27] showed, by using 1 H, 13 C and 31 P solution state NMR, that no P\O\P or P\O\Si bonds were present in PO(OEt) 3 /Si(OEt) 4 sols. The presence of P\O\Si bonds was evidenced only in gels by using static 31 P NMR: the shielding of 31 P resonances (up to ≈−28 ppm, when compared to ≈0 ppm for orthophosphate species) was explained by this type of bonding.…”

“…Other physical and chemical analyses of these materials were already presented in a previous paper [13].…”

“…Previous author's work [13] studied the thermal and structural evolution of sol-gel derived silico-phosphate compounds with heat treatment by means of thermogravimetric and differential thermal analyses and X-ray diffraction analysis. Additionally, the work aimed at assessing the microstructural changes occurring on the heat treated sol-gel samples by scanning electron microscopy.…”

Preparation of P2O5-SiO2 hollow microspheres in the presence of phosphoric acid

“…The structural, optical and electrical characteristics of SiO 2 -P 2 O 5 materials obtained by sol-gel methods have been studied. Various siliconphosphates structures have been formed during different preparation methods [10,11]. However, to the best of our knowledge, the fabrication of P 2 O 5 /SiO 2 silica hollow spheres has not been reported.…”