Ultrasonic-phase-velocity measurements in electron-irradiated quartz
Precision measurements of the ultrasonic velocity change as a function of temperature were carried out in electron-irradiated quartz (dose = 1.0 x 10/sup 20/ e/cm/sup 2/, E = 3 MeV) for two frequencies: 648 and 480 MHz. Between 0.33 and 2 K, a frequency-independent logarithmic increase of the velocity is observed. The effect is very small, but clearly indicates the presence of the resonant interaction of tunneling states with phonons. The experiment shows that tunneling states of a two-state nature are present. In addition, the effect of the relaxation process on the velocity is observed and shows that the tunneling states are of the same nature as in glasses. A comparison with neutron-irradiated quartz indicates that similar tunneling states are induced by electrons and neutrons, in spite of the different disordering processes. It is suggested that the electron-induced Frenkel pairs provide the necessary freedom for rearrangements and rotations of the tetrahedra, which can be at the origin of the tunneling states.
- Research Organization:
- Laboratorium voor Vaste Stof- en Hoge Druk-Fysika, Departement Natuurkunde, Katholieke Universiteit Leuven, Celestijnenlaan 200D, B-3030 Leuven, Belgium
- OSTI ID:
- 6478776
- Journal Information:
- Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 39:6; ISSN PRBMD
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
360605* -- Materials-- Radiation Effects
CHALCOGENIDES
ELECTRONS
ELEMENTARY PARTICLES
FERMIONS
LEPTONS
MINERALS
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
PHASE VELOCITY
PHONONS
PHYSICAL RADIATION EFFECTS
QUARTZ
QUASI PARTICLES
RADIATION EFFECTS
SILICON COMPOUNDS
SILICON OXIDES
SOUND WAVES
TEMPERATURE DEPENDENCE
TUNNEL EFFECT
ULTRALOW TEMPERATURE
ULTRASONIC WAVES
VELOCITY
WAVE PROPAGATION