The vibrational dynamics of lutetium orthophosphate (LuPO4) single crystals was carefully investigated by means of polarized micro-Raman spectroscopy and ab initio calculations. Eleven of the twelve independent components of the polarizability tensor, expected on the basis of the group theory for LuPO4, were selected in turn and assigned in symmetry. The only B1g(2) Raman mode was not observed, likewise due to either its very small intensity or its nearness in energy with forbidden Raman modes, which spill and could hide it. Both Raman and infrared vibrational modes are evaluated by densityfunctional theory calculations using effective core pseudo-potential. The agreement between calculated and experimental frequencies is very good. On the basis of our ab initio results, and of reduced-mass ratio considerations, the expected wavenumber of the missing B1g (2) mode falls close to that of Eg(3) mode peaked at about 306 cm1, and therefore we can definitively conclude that the observation of the missing B1g (2) mode is masked by the spill-over of this Eg mode.

Polarized micro-Raman spectroscopy and ab initio phonon modes calculations of LuPO4

SANSON, Andrea;GIAROLA, Marco;BETTINELLI, Marco Giovanni;SPEGHINI, Adolfo;MARIOTTO, Gino
2013

Abstract

The vibrational dynamics of lutetium orthophosphate (LuPO4) single crystals was carefully investigated by means of polarized micro-Raman spectroscopy and ab initio calculations. Eleven of the twelve independent components of the polarizability tensor, expected on the basis of the group theory for LuPO4, were selected in turn and assigned in symmetry. The only B1g(2) Raman mode was not observed, likewise due to either its very small intensity or its nearness in energy with forbidden Raman modes, which spill and could hide it. Both Raman and infrared vibrational modes are evaluated by densityfunctional theory calculations using effective core pseudo-potential. The agreement between calculated and experimental frequencies is very good. On the basis of our ab initio results, and of reduced-mass ratio considerations, the expected wavenumber of the missing B1g (2) mode falls close to that of Eg(3) mode peaked at about 306 cm1, and therefore we can definitively conclude that the observation of the missing B1g (2) mode is masked by the spill-over of this Eg mode.
Luthetium orthophosphate; vibrational dynamics; Raman micro-spectroscopy; ab-initio calculations
File in questo prodotto:
File Dimensione Formato  
JRS 44 (10) (2013) 1411-1415.pdf

accesso aperto

Tipologia: Documento in Post-print
Licenza: Dominio pubblico
Dimensione 215.6 kB
Formato Adobe PDF
215.6 kB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11562/543550
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 7
  • ???jsp.display-item.citation.isi??? 7
social impact