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Dynamical properties of crystals of Sr(NO 3 ) 2 , Ba(NO 3 ) 2 , and Pb(NO 3 ) 2 . I. Infrared spectra and structure
Author(s) -
Bon A. M.,
Benoit C.,
Bernard O.
Publication year - 1976
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2220780104
Subject(s) - phonon , polariton , reflection (computer programming) , infrared , spectral line , infrared spectroscopy , condensed matter physics , physics , materials science , chemistry , optics , quantum mechanics , computer science , programming language
The far infrared reflection spectra of three single crystals of Sr(NO 3 ) 2 , Ba(NO 3 ) 2 , and Pb(NO 3 ) 2 are measured from 2500 to 10 cm −1 and from 10 to 300 K. The results are discussed on the basis of phonon and polariton theory. A method is found to determine the number of ordinary and extraordinary phonons in the case of general symmetry and a relation is established between the phonon frequencies and the polariton frequencies. These results are applied to discuss the spectra of Sr(NO 3 ) 2 , Ba(NO 3 ) 2 , and Pb(NO 3 ) 2 . Then, among several structures proposed by different authors, the T 4 structure is proposed from the results.