Journal of physics Condensed matter vol:12 issue:37 pages:8135-8143
Ultrasonic attenuation measurements were performed on fast-neutron irradiated bulk silicon. The data are analysed in the framework of the tunnelling model. Good agreement was found with the results obtained from earlier measurements of the changes in ultrasonic velocity, performed on the same samples, and the presence of tunnelling states in this material was confirmed. More detailed analysis however gives an indication of the presence of two different types of tunnelling state.