Study on Europium-Doped Hydroxyapatite Nanoparticles by Fourier Transform Infrared Spectroscopy and Their Antimicrobial Properties

Table 1

IR wavenumber position (cm⁻¹) of 𝜈₄, 𝜈₃, 𝜈₂, and 𝜈₁ [PO₄]³⁻ bands of Eu:HAp spectrum from second derivative.

Assignments	Position (cm^−1)	References
𝜈1 [PO4]^3−	962	[62]
𝜈2 [PO4]^3−	475	[62]
𝜈3 [PO4]^3−	1033; 1045; 1073; 1090	[62]
𝜈4 [PO4]^3−	569; 575; 588; 602	[62]
Present in newly precipitated apatite	1111	[62, 74]
[HPO4]^2−-containing apatites	1144	[74]
[OH]^− group (librational mode)	633	[74, 75]