Decomposition activation of hydroxyapatite in contact with β-tricalcium phosphate

Скороход, В. В.; Solonin, S. M.; Dubok, V. A.; Kolomiets, L. L.; Permyakova, T. V.; Shinkaruk, A. V.

doi:10.1007/s11106-010-9239-z

Cited by 13 publications

(8 citation statements)

References 5 publications

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“…In the powder pattern of sample Eu-HAp900, some unindexed peaks were detected after the structure refinement of the HAp phase; these were assigned to the Ca 3 (PO 4 ) 2 (TCP) phase [31], which was included in the calculations but not refined; quantitative phase analysis carried out by EXPO2013 gave HAp 88.9% and TCP 11.1% in the sample. This result is in agreement with the finding of [32,33] who reported partial dissociation of HAp into TCP at about 900 • C, and with previous investigations on TCP [7,34]. Crystal structure refinements data are reported in Table 2, while in Figure 1 the agreement between the observed (blue line) and the calculated (red line) diffraction pattern is displayed together with the difference pattern plotted on the same scale (violet line) and background (green line) for sample Eu-HAp900 (a), Eu-HAp450 (b) and Eu-HAp120 (c).…”

Section: X-ray Structural Studysupporting

confidence: 94%

Crystal Chemistry and Luminescence Properties of Eu-Doped Polycrystalline Hydroxyapatite Synthesized by Chemical Precipitation at Room Temperature

et al. 2020

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Europium-doped hydroxyapatite Ca10(PO4)6(OH)2 (3% mol) powders were synthesized by an optimized chemical precipitation method at 25 °C, followed by drying at 120 °C and calcination at 450 °C and 900 °C. The obtained nanosized crystallite samples were investigated by means of a combination of inductively coupled plasma (ICP) spectroscopy, powder X-ray diffraction (PXRD), Fourier Transform Infrared (FTIR), Raman and photoluminescence (PL) spectroscopies. The Rietveld refinement in the hexagonal P63/m space group showed europium ordered at the Ca2 site at high temperature (900 °C), and at the Ca1 site for lower temperatures (120 °C and 450 °C). FTIR and Raman spectra showed slight band shifts and minor modifications of the (PO4) bands with increasing annealing temperature. PL spectra and decay curves revealed significant luminescence emission for the phase obtained at 900 °C and highlighted the migration of Eu from the Ca1 to Ca2 site as a result of increasing calcinating temperature.

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Section: X-ray Structural Studysupporting

confidence: 94%

Crystal Chemistry and Luminescence Properties of Eu-Doped Polycrystalline Hydroxyapatite Synthesized by Chemical Precipitation at Room Temperature

et al. 2020

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“…The indexing of the powder diffraction patterns by N-TREOR09 program [38], as integrated in EXPO, revealed a hexagonal unit cell typical of HA, with some unindexed diffraction peaks attributed to Ca 3 (PO 4 ) 3 tricalcium phosphate (TCP) phase. The mixture is in agreement with [39] reporting a partial dissociation of HA into TCP at about 900 • C.…”

Section: X-ray Structural Studysupporting

confidence: 90%

Characterization and Luminescence of Eu3+- and Gd3+-Doped Hydroxyapatite Ca10(PO4)6(OH)2

et al. 2020

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Luminescence properties of europium-doped Ca10-xEux(PO4)6(OH)2 (xEu = 0, 0.01, 0.02, 0.10 and 0.20) and gadolinium-doped hydroxyapatite Ca9.80Gd0.20(PO4)6(OH)2 (HA), synthesized via solid-state reaction at T = 1300 °C, were investigated using scanning electron microscopy (SEM), powder X-ray diffraction (PXRD), Fourier transform infrared (FTIR), and luminescence spectroscopy. Crystal structure characterization (from unit cell parameters determination to refined atomic positions) was achieved in the P63/m space group. FTIR analyses show only slight band shifts of (PO4) modes as a function of the rare earth concentration. Structural refinement, achieved via the Rietveld method, and luminescence spectroscopy highlighted the presence of dopant at the Ca2 site. Strong luminescence was observed for all Eu- and Gd-doped samples. Our multi-methodological study confirms that rare-earth (RE)-doped synthetic hydroxyapatites are promising materials for bio-imaging applications.

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“…These results reveal that in addition to sintering temperature, the phase composition of coatings depends on the starting TCP concentration. This is also expressed in other researchers' reported results [23,24]. The formula expressed in equation 2can be used to show the decomposition of HAp [23]:…”

Section: Phase Evaluation Of Coatingmentioning

confidence: 78%

Sintering behaviour and interfacial toughness of HAp/TCP coatings on HAp/Ti nanocomposite substrates

et al. 2019

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Spark plasma sintering (SPS) is used in rapid compaction of materials in order to achieve higher compact density and in improving mechanical strength and toughness. However, implants produced by SPS do not have preferred positions for formation of a bone-like apatite layer on their surface due to their high density. Biphasic-calcium phosphate (BCP) ceramics consisting of stable hydroxyapatite (HAp) and soluble tri-calcium phosphate (TCP) are developed to achieve a controllable biodegradation rate and biological stability by adjusting the TCP/HAp ratio. The primary goal of this study is to improve mechanical properties and bioactivity of implants. HAp/20 wt% Ti nanocomposite powders were chosen for bulk, and also HAp/TCP nanocomposite powders were chosen for coatings with weight percentages of 75/25, 50/50 and 25/75, respectively. The samples were sintered for 5 min at a compaction pressure of 30 MPa and at different temperatures of 650 and 750 • C. The phase changes of the coatings are studied by X-ray diffraction. Mechanical properties such as interfacial toughness are investigated. The results show that amount of TCP increases with increasing sintering temperature in HAp/ 75 wt% TCP coating, however no significant change was observed in amount of TCP in HAp/25 wt% TCP coating. Also, the maximum value of interfacial toughness is equal to 34 MPa mm 1/2 , which was obtained for 75 wt% HAp-25 wt% TCP coating sintered at 750 • C.

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Decomposition activation of hydroxyapatite in contact with β-tricalcium phosphate

Cited by 13 publications

References 5 publications

Crystal Chemistry and Luminescence Properties of Eu-Doped Polycrystalline Hydroxyapatite Synthesized by Chemical Precipitation at Room Temperature

Crystal Chemistry and Luminescence Properties of Eu-Doped Polycrystalline Hydroxyapatite Synthesized by Chemical Precipitation at Room Temperature

Characterization and Luminescence of Eu3+- and Gd3+-Doped Hydroxyapatite Ca10(PO4)6(OH)2

Sintering behaviour and interfacial toughness of HAp/TCP coatings on HAp/Ti nanocomposite substrates

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