Isotope Effects on the Raman Spectrum of SiC

Beitrag in einer Fachzeitschrift


Details zur Publikation

Autor(en): Hundhausen M, Ley L
Zeitschrift: Materials Science Forum
Verlag: Trans Tech Publications
Jahr der Veröffentlichung: 2000
Band: 338-342
Seitenbereich: 579
ISSN: 0255-5476
eISSN: 1662-9752


Abstract

Substituting 12C by the 13C isotope in SiC changes the Raman frequencies. We have used isotopic substitution in several polytypes of SiC (4H, 6H, 15R) to study the change in the phonon dispersion relation of SiC and compare the results with calculations based on a linear-chain model. In a second set of experiments we use isotopic substitution to study the incorporation of carbon from the crucible during the growth of SiC by the modified Lely technique. To this end, a stoichiometric mixture of silicon and pure 13C was used as the charge. The incorporation of 13C in the grown crystal as monitored by spatially resolved Raman spectroscopy yields a gradient of 13C that increases beginning at the seed crystal and reaches a maximum of approximately 40% within 300 μm; the equilibrium concentration of 13C is a mere 27% after 1.5 mm growth.


FAU-Autoren / FAU-Herausgeber

Hundhausen, Martin apl. Prof. Dr.
Lehrstuhl für Laserphysik
Ley, Lothar Prof. Dr.
Naturwissenschaftliche Fakultät

Zuletzt aktualisiert 2018-09-08 um 19:38