Association and Bound Motion in Alkali Metal Doped Cadmium Fluoride.
Interim technical rept.,
NAVAL ACADEMY ANNAPOLIS MD DEPT OF PHYSICS
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The effects of temperature and hydrostatic pressure on the ionic conductivity and the dielectric relaxation have been measured for lithium-, sodium-, and potassium-doped cadmium fluoride. Activation energies and activation volumes for the association region and for motion of the bound defects have been determined. These were found to depend strongly on the size of the dopant. for the nominally sodium doped material a single relaxation attributable to sodium is observed and is associated with NN fluorine vacancy-sodium substitutional pairs. For the potassium doped material, two distinct relaxations are observed, which suggest the presence of both NN and NNN fluorine vacancy-potassium substitutional dipoles. A single relaxation peak is observed in the lithium doped material. It is attributed either to NN fluorine vacancy-substitutional lithium pairs or to lithium interstitial-lithium substitutional complexes. The activation energy for jumps of bound vacancies is largest for the sodium dopant for which the distortion is the least. The activation energies and the activation volumes for bound vacancy motion were found to be approximately in the same ratio as the values reported for free vacancy motion as expected from dynamical diffusion theories. Author
- Atomic and Molecular Physics and Spectroscopy