Temperature dependence of photoacoustic spectra of C sub(60) and C sub(70) crystals

Temperature dependence of photoacoustic spectra of C sub(60) and C sub(70) crystals

The photoacoustic (PA) spectra of undoped C sub(60) and C sub(70) crystals have been measured as a function of temperature, 35 approx. 300 K, and chopping frequency. At room temperature, PA signal edges associated with abrupt increases are found near 1.8 eV. With a decrease in temperature, a tail ap...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:The Journal of physics and chemistry of solids 1994-01, Vol.55 (9), p.835-841
Hauptverfasser: Matsuura, Seiji, Tsuzuki, Takuya, Ishiguro, Takehiko, Endo, Hirohisa, Kikuchi, Koichi, Achiba, Yoji, Ikemoto, Isao
Format: Artikel
Sprache:eng
Schlagworte:
Crystals
Molecular structure
Optical properties
Phase transitions
Photoacoustic spectroscopy
Relaxation processes
Thermal effects
Thermodynamic properties
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:The photoacoustic (PA) spectra of undoped C sub(60) and C sub(70) crystals have been measured as a function of temperature, 35 approx. 300 K, and chopping frequency. At room temperature, PA signal edges associated with abrupt increases are found near 1.8 eV. With a decrease in temperature, a tail appears near the lower energy side of the PA signal edge for both C sub(60) and C sub(70), where structures reflecting the molecular vibronic modes are superposed. Solid state effects are observed clearly for C sub(60) as a discontinuous shift of the PA edge by approx. 0.02 eV at 260 K corresponding to structural transformation and as a relaxation effect on change of molecular configuration.
ISSN:0022-3697