Thermal Expansion of Silicon and Zinc Oxide (I)

Abstract A new expansion cell for the three‐terminal capacitance method is developed. Length changes in the order of 10 −9 cm can be measured at samples of only 4 mm. At first the expansion coefficient of silicon (reference material) is investigated in detail from 20 to 300 °K. The work is completed by interferometric measurements up to 800 °K. The temperature dependence of the expansion coefficient is discussed using the thermal equation of state. Furthermore conclusions are drawn concerning the contributions of different phonon branches and compared to calculations on the basis of well‐known models.