Second-order Raman spectra of a LiNbO3:Tb crystal

N V Sidorov; M N Palatnikov; V S Gorelik; P P Sverbil

doi:10.1016/j.saa.2021.120445

Second-order Raman spectra of a LiNbO₃:Tb crystal

Spectrochim Acta A Mol Biomol Spectrosc. 2022 Feb 5:266:120445. doi: 10.1016/j.saa.2021.120445. Epub 2021 Sep 27.

Authors

N V Sidorov¹, M N Palatnikov², V S Gorelik³, P P Sverbil³

Affiliations

¹ Tananaev Institute of Chemistry - Subdivision of the Federal Research Centre «Kola Science Centre of the Russian Academy of Sciences», 184206 Apatity City, Russia. Electronic address: n.sidorov@ksc.ru.
² Tananaev Institute of Chemistry - Subdivision of the Federal Research Centre «Kola Science Centre of the Russian Academy of Sciences», 184206 Apatity City, Russia.
³ P.N. Lebedev Physical Institute of the Russian Academy of Sciences, 119991 Moscow, Russia.

PMID: 34619512
DOI: 10.1016/j.saa.2021.120445

Abstract

Additional bands have been discovered for the first time in the Raman spectra of terbium doped lithium niobate crystals. The bands have been determined in the high-frequency region and have been attributed to the overtone states of the second order of polar fundamental modes of the crystal lattice. It has been established that Raman spectrum of terbium doped lithium niobate contains bands with frequencies exceeding the overtones of the highest-frequency fundamental polar modes of A₁(Z) and E(X, Y) symmetry types. The observed features of the second-order Raman spectra have been interpreted as a manifestation of bound states of phonons - biphonons.

Keywords: Biphonon; Doping; Lithium niobate; Raman scatting; Second order; Threshold concentration.