High mechanical Q-factor measurements on calcium fluoride at cryogenic temperaturesR. Nawrodt, A. Zimmer, T. Koettig, S. Nietzsche, M. Thürk, W. Vodel and P. SeidelEur. Phys. J. Appl. Phys., 38 1 (2007) 53-59DOI: https://doi.org/10.1051/epjap:2007040