https://doi.org/10.1007/s100510050085
Ab initio study of phonons in the rutile structure of SnO2 under pressure
Institute for Materials Research,
Tohoku University,
2-1-1 Katahira, Sendai 980-8577, Japan
Received:
18
July
1999
Published online: 15 February 2000
Using the local-density approximation,
calculating the Hellmann-Feynman forces and
applying the direct method,
the phonon dispersion relations for
the rutile-like structure of crystalline SnO2
have been derived for the first time.
The phonon frequencies at the point agree very well
with Raman and infrared data and other phenomenological model
calculations.
The LO/TO splitting is estimated by
calculating phonons from an elongated supercell.
The computations under pressure reveal a soft mode of
B
symmetry which leads to a ferroelastic phase
transition.
The pressure-dependence of the lattice constants and
the Grüneisen
parameters of the modes are calculated.
PACS: 63.20.-e – Phonons in crystal lattices / 71.15.Mb – Density functional theory, local density approximation / 62.50.+p – High-pressure and shock-wave effects in solids and liquids
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2000