Determination of Precise Unit‐Cell Parameters of the α‐Tricalcium Phosphate Ca₃(PO₄)₂ Through High‐Resolution Synchrotron Powder Diffraction

Abstract

Unit‐cell parameters of the α‐tricalcium phosphate [TCP; Ca3(PO4)2] were investigated using high‐resolution synchrotron powder diffraction and the Rietveld method. The diffraction experiment was conducted at 29°C at the BL‐15XU experimental station of SPring‐8, Japan. Precise unit‐cell parameters of the α‐TCP were obtained; a=12.87271 (9), b=27.28034(8), c=15.21275(12) Å, α=γ=90°, and β=126.2078(4)°. The calculated density of α‐TCP (2.8677 g/cm3) is smaller than that of β‐TCP, indicating the “looser” structure of α‐TCP.

Phase Transformation in Ca3(PO4)2:Eu2+ via the Controlled Quenching and Increased Eu2+ Content: Identification of New Cyan‐Emitting α‐Ca3(PO4)2:Eu2+ Phosphor

“…) is very complex and has a big unit cell consisting of 18 independent calcium, 48 oxygen and 12 phosphorus sites. The cell parameters of α‐TCP have been determined as a = 12.87271(9), b = 27.28034(8), c = 15.21275(12) Å, V = 4310.59(5) Å 3 , α = γ = 90°, and β = 126.2078(4) ° . The crystal structure of β‐TCP has also been well studied: it has the space group of R 3 c (no.…”

“…The cell parameters of a-TCP have been determined as a = 12.87271(9), b = 27.28034 (8), c = 15.21275 (12) A, V = 4310.59(5) A 3 , a = c = 90°, and b = 126.2078(4)°. 17 The crystal structure of b-TCP has also been well studied: 20 it has the space group of R3c (no. 161) and is of higher structural symmetry in comparison to that of a-TCP.…”

“…. The known α‐ and β‐TCP crystal structures were used as starting models in the refinements. In Fig.…”

A facile method to in situ formation of hydroxyapatite single crystal architecture for enhanced osteoblast adhesion

“…a-TCP has a monoclinic crystal structure (space group P2 1 /a). 33 The different distributions of Ca atoms in the a-TCP result in its solubility being much higher when compared to that of b-TCP. 34 Additionally, as the space group of a-TCP is identical to that of monoclinic HAp (P2 1 /b), a-TCP can transform into HAp by replacing the Ca 2+ -Ca 2+ columns at the edges of the unit cell with anionic OH À columns.…”

Bioceramic Materials

“…α -TCP crystallizes in the monoclinic space group P2 1 /a as a large unit cell with parameters a = 1.287 271(9) nm, b = 2.728 034(8) nm, c = 1.521 275(12) nm, β = 126.2078(4) ° , and Z = 24 (Yashima et al ., 2007 ) [1000]…”