A Study of the Transport of Thermal Acoustic Phonons in CaF 2 Single Crystals and Ceramics within the Subterahertz Frequency Range

摘要

We performed a comparative study of the phonon transport characteristics in the subterahertz frequency range for CaF 2 ceramic (natural and artificial) and single crystalline samples. It was demonstrated that, in the helium temperature range, the thermal characteristics of artificial ceramics are comparable to those of single crystals. The thickness of domain boundaries in natural ceramics was estimated.