Hyper‐Raman spectroscopy of CeO 2

• Published in: Journal of Raman spectroscopy Vol. 51; no. 7; pp. 1260 - 1263
• Main Authors: Villa‐Aleman, Eliel, Houk, Amanda L., Dick, Don D., Hunyadi Murph, Simona E.
• Format: Journal Article
• Language: English
• Published: Netherlands Wiley Blackwell (John Wiley & Sons) 01.07.2020
• ISSN: 0377-0486; 1097-4555
• DOI: 10.1002/jrs.5886

Abstract Cerium dioxide (CeO 2 ) belongs to the fluorite structure group ( O h 5 point group) resulting in one Raman active T 2g mode and two IR active T 1u TO and LO modes. The T 2g Raman band in CeO 2 has been used to probe the symmetric Ce–O vibrational mode of different sized nanoparticulates. Far infrared studies of the Ce–O interactions are difficult to conduct because of low optical transmission, efficiency of the detector, and water absorption bands interfering with the measurements. The selection rules of hyper‐Raman spectroscopy (HRS) allow the study of IR bands in the far infrared spectral region, such as the motion of the Ce atoms. For the first time, HRS was used to investigate the T 1u TO and LO IR modes in CeO 2 . The position and full‐width half‐maximum (FWHM) of the TO and LO bands in the HRS spectrum were used to investigate the spectral response in relation to particle size (i.e., phonon confinement). The investigation of CeO 2 with HRS provides a research platform for future work in the study of ThO 2 , UO 2 , and PuO 2 IR modes.