Abstract :
By means of a steady-state heat-flow technique, we have measured the thermal conductivity in a bulk crystal of highly enriched (99.8588%) 28Si for temperatures between 2 and 310 K. Maximum values of about 30 000 W m−1 K−1 for κ are found around 20 K. This is six times larger than in natural silicon and even exceeds the maximum in diamond with natural isotope abundance. At room temperature, we obtain a thermal conductivity enhancement of almost 60% compared to natural Si. Our results agree well with theoretical predictions.
