The influence of trace magnesium content on the phase composition of silicon-stabilized calcium phosphate powders

A novel silicon-stabilized calcium phosphate phase mixture possesses a characteristic phase composition of ∼ 75 wt.% silicon-stabilized α-tricalcium phosphate (Si-α-TCP) with the balance being calcium hydroxyapatite (HA) and traces of β-tricalcium phosphate (β-TCP). Variability in the phase composition has been shown to be caused by trace magnesium (Mg) contained in the calcium nitrate tetrahydrate used to prepare the sol gel. Mg contents between 250 and 300 ppm are sufficient to form significant quantities of β-TCP at the expense of the Si-α-TCP phase.