Table 3.

IR band assignment of HA.

Wavenumber (cm−1)	Peak Assignment
3571	Band corresponding to H2O absorption
1455	ν3 stretching mode of CO32−
1410	ν3 carbonate ions
1090	ν3 asymmetric stretching mode of P–O
1025	ν3 asymmetric stretching mode of P–O
962	ν1 symmetric stretching mode of P–O
879	ν2 bending mode of carbonate ions
630	δ in-plane vibration of OH−
601	ν4 triply degenerate bending mode of PO43− (O–P–O)
563	ν4 triply degenerate bending mode of PO43− (O–P–O)