TITLE: Dynamics of Dipolar Defects in Rare Earth Doped Alkaline-Earth Fluoride Crystals

SPEAKER: Forrest Taylor Charnock,

Doping alkaline-earth fluoride crystals with rare earth ions often creates dipolar defects in the lattice. These consist of a substitutional rare earth ion (R³⁺) along side an interstitial F^- ion. I have studied these materials using EPR, dielectric, and optical techniques. Given sufficient thermal energy, the interstial F^- may move among the adjacent interstitial sites and thus reorient the dipole; I have recently found that this motion may also be stimulated optically.