Naslov
Density functional theory demonstrates orientation effects in the Raman spectra of hydroxy- and carbonated apatite
(Density functional theory demonstrates orientation effects in the Raman spectra of hydroxy‐ and carbonated apatite)

Autori
Gemeri, Dejan ; Živković, Aleksandar ; Lukačević, Igor ; Bahmann, Hilke ; King, Helen E.

Izvornik
Journal of Raman Spectroscopy (0377-0486) 54 (2023); 159-170

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Raman spectroscopy ; Density functional theory ; Apatites ; Orientation effects

Sažetak
Raman spectroscopy is widely used to examine the carbonate content within bone apatite, but Raman spectra are also sensitive to orientation effects between the polarisation of the incoming laser light and the sample orientation. This may lead to discrepancies when using Raman spectroscopy to evaluate the carbonate content as the extent of crystal organisation can change depending on the type of bone, age, and presence of mineralisation disorders in the organism. It is experimentally very challenging to evaluate the effect of orientation using individual bone crystals. Therefore, we have used density functional theory to examine the effect of orientation in apatitic materials. Our simulations show that the OH group in hydroxyapatite has a strong orientation dependence, consistent with previous literature. In addition, the phosphate and carbonate bands of the apatitic structures are predicted to be orientation dependent, where the maximum scattering efficiency occurs in configurations in which the laser polarisation is parallel to the crystallographic axes of the material. The intensity changes of the phosphate and carbonate bands are not consistent upon changing orientations and thus may lead to an underestimation of carbonate contents if insufficient sampling points are used during bone analysis.

Izvorni jezik
Engleski

Znanstvena područja
Fizika, Kemija

POVEZANOST RADA