Hole burning and optically detected fluorine nmr in pr3+: Caf2

The interactions between Pr3+ ions in a tetragonal site of 0.01-at.% Pr3+ and the surrounding nuclei are investigated, primarily by means of optically detected NMR (ODNMR). This technique is based on the fact that hole burning in the 5941- H43"D21 transition takes place due to coupling between the rare-earth ion and neighboring F19 nuclear spins. ODNMR lines are identified which are due to nearest-neighbor (NN), next-nearest-neighbor (NNN), and interstitial (i) fluorines. The distorted positions of the NNN fluorines are determined from the ODNMR data, but this is impossible for the other near neighbors due to strong covalent-bonding effects. Physical models for the hole-burning and refilling processes are proposed which agree qualitatively with the hole shapes and ODNMR line intensities, and with the observation of rf-assisted optical hole burning when a strong magnetic field H0 is applied parallel to C4. © 1982 The American Physical Society.