Low-temperature thermal expansion of crystalline ortho-terphenyl

Abstract

The thermal expansion of polycrystalline ortho-terphenyl has been measured in the range 9 K ˇ- T ˇ- 30K. A strong lattice contraction occurs for most temperatures in this range. The microscopic origins of such anharmonic effects are discussed on qualitative grounds on the basis of recent Raman measurements. the relevance of the present findings for glassy dynamics are also addressed.