Synthesis and Mechanism of Tetracalcium Phosphate from Nanocrystalline Precursor

Table 1

Vibrational wave numbers [cm⁻¹] of samples.

	Raman; = 514.5 nm	FT-IR; KBr	Assignments
1400~1500°C; ×8 h	327		Lattice modes
	390, 408, 448, 481	454, 470, 501	, bands in TTCP, symmetric bending vibrations mode
	555, 565, 577, 598, 608, 616	570, 593, 621	ν 4, bands in TTCP, asymmetric bending vibrations mode
	941, 948, 957, 963	938, 958	ν 1, bands in TTCP, symmetric stretching mode
	992, 1010, 1027, 1046,; 1075, 1095, 1122, 1135	985, 1009, 1031, 1045, 1063, 1074, 1094, 1105	ν 3, bands in TTCP, asymmetric stretching mode
850–1150°C; ×8 h	430, 445	431, 471	ν 2, bands in HA
	579, 590, 607	604	ν 4, bands in HA
		634	Vibrational mode of OH^−
		871	Out-of-plane bending vibrations of
	961	961	ν 1, bands in HA
	1028, 1046, 1075, 1123	1025, 1091	ν 3, bands in HA
	1085		Symmetric stretching of
		1412, 1452, 1467	Asymmetric stretching of
	3572	3572	OH^− stretching vibration (in HA)
	3619	3643	OH^− stretching vibration (in Ca(OH)2)