Slow dynamics and instability ins
Publikation: Bidrag til tidsskrift › Tidsskriftartikel › Forskning › fagfællebedømt
The low-frequency dynamics of (Formula presented) has been investigated in the temperature range T=300-15 K. The dispersion surfaces at room temperature display a deep valley located along the (0.5, ζ, 0.5) zone-boundary line. This valley becomes deeper when T decreases, showing a soft-mode behavior. In addition a new depression appears at low-temperature along the (ξ, 0.5, 0.5) line, corresponding to an incipient instability toward an incommensurate phase. A symmetry analysis of the vibration spectrum including the compatibility relations between the different irreducible representations, is presented. The soft-mode symmetry is determined as belonging to the (Formula presented) representation. The present results are compared to previous Raman and x-ray investigations performed on this compound.
Originalsprog | Engelsk |
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Tidsskrift | Physical Review B - Condensed Matter and Materials Physics |
Vol/bind | 55 |
Udgave nummer | 13 |
Sider (fra-til) | 8249-8256 |
Antal sider | 8 |
ISSN | 1098-0121 |
DOI | |
Status | Udgivet - 1 jan. 1997 |
Eksternt udgivet | Ja |
ID: 209602352