Regensburg 2004 – scientific programme
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HL: Halbleiterphysik
HL 51: Si/Ge
HL 51.3: Talk
Friday, March 12, 2004, 12:00–12:15, H17
Thermal Conductivity of Isotopically Enriched 28Si: Revisited — •R. K. Kremer1, M. Cardona1, H.-J. Pohl2, G. G. Devyatych3, and P. G. Sennikov3 — 1MPI für Festkörperforschung, Heisenbergstr. 1, D-70569 Stuttgart, Germany — 2VITCON Projectconsult GmbH, Otto-Schott-Str. 13, D-07745 Jena, — 3Institute of Chemistry of Highly-Pure Substances, Russian Academy
The thermal conductivity of isotopically enriched 28Si recently has attracted particular attention because of a claim of a 60% higher room-temperature thermal conductivity of 28Si as compared to that of Si with a natural isotope mixture natSi [1]. It was argued, however, that this result cannot be reconciled with theoretical estimates which give, at most, a 20% increase. Because of the potential technological importance of a significantly larger thermal conductivity of isotopically pure samples of Si we have, with a steady-state heat-flow technique, redetermined the thermal conductivity of the previously measured samples and new single crystal samples of 28Si and natSi between 10K and 320K. To estimate and reduce the disturbing influence of thermal radiation losses at elevated temperature we have particularly taken care to utilize samples with identical geometrical dimensions. Close to room-temperature we consistently find an increase in the thermal conductivity of 28Si with respect of that of natSi of about 10 ± 2 %, whereas the values of this enhancement below 100K are close to that reported in ref. [1].
[1] T. Ruf et al., Solid State Commun., 115, 243 (2000).