Premium
On the Polarization Vectors of Lattice Vibrations
Author(s) -
Grimvall G.
Publication year - 1969
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.19690320139
Subject(s) - anisotropy , lattice vibration , condensed matter physics , lattice (music) , transverse plane , polarization (electrochemistry) , vibration , physics , cubic crystal system , materials science , optics , chemistry , quantum mechanics , phonon , engineering , structural engineering , acoustics
The polarization vectors of lattice vibrations in anisotropic crystals of cubic structure are considered from a quantitative point of view. A new anisotropy index A = c 11 /( c 12 + 2 c 44 ) is shown to be more adequate as a measure of anisotropy than the conventional s = ( c 11 — c 12 )/2 c 44 . The reason for anisotropy is discussed briefly, with special emphasis on simple metals. The approximation of assuming the lattice vibrations to be strictly longitudinal or transverse is discussed for several properties of metals, with sodium taken as an example.