Abstract

A round robin was conducted in which the thermal conductivities of ten specimens of CVD diamond were measured. Four companies supplied the specimens and ten laboratories performed the measurements. The average values of all measurements on a specimen ranged from 420 W·m⁻¹·K⁻¹± 32% for the least conductive specimen to 1660 W·m⁻¹·K⁻¹± 34% for the most conductive specimen. The measured values showed large laboratory to laboratory variations in many instances. Significant specimen inhomogeneity was also found. One laboratory measured thermal conductivity anisotropy which was found to be significant. The large variations observed might be attributable to specimen inhomogeneity and to the manner in which the different techniques sampled the thermal conductivity distribution.