Eur. Phys. J. B 10, 623-633 (1999)
https://doi.org/10.1007/s100510050894

Low frequency elastic properties of neutron-irradiated quartz. Comparison with glasses^*

¹ Institut für Angewandte Physik, Universität Heidelberg, Albert-Ueberle-Strasse 3-5, 69120 Heidelberg, Germany
² Department of Physics, Katholieke Universiteit Leuven, Celestijnenlaan 200D, 3001 Leuven, Belgium

Corresponding author: ^a classen@urz.uni-heidelberg.de

Received: 23 October 1998
Published online: 15 August 1999

Abstract

Neutron-irradiated quartz is a promising model system to learn more about the low-energy excitations (tunneling states) in vitreous silica and in similar glasses. We present the first systematic study of the elastic properties of neutron-irradiated quartz at low frequencies and very low temperatures. Using the vibrating reed technique at frequencies of several kHz we have measured the sound velocity and internal friction of six quartz crystals irradiated with different neutron doses over a wide range of temperatures (7 mK-300 K). The results are analyzed using the tunneling model and several extensions of this theory. Comparisons are made with recent low-frequency measurements on normal and compacted vitreous silica and with ultrasound experiments on neutron-irradiated quartz.