Thermal conductivity measurement from 30 to 750 K: the 3ω method

An ac technique for measuring the thermal conductivity of dielectric solids between 30 and 750 K is described. This technique, the 3ω method, can be applied to bulk amorphous solids and crystals as well as amorphous films tens of microns thick. Errors from black-body radiation are calculated to be less than 2% even at 1000 K. Data for a-SiO2, Pyrex 7740, and Pyroceram 9606 are compared to results obtained by conventional techniques.