Determination of Off-Center Displacements in NaBr:F~- by Nuclear Magnetic Double Resonance

摘要

The measurements of the quadrupole splittings of Na~+ ion in NaBr:F~- crystal are performed by nuclear magnetic double resonance. The electric field gradients produced by lattice distortion at the Na nuclei in the vicinity of the substitutional F~- impurity ion is obtained, and the displacement of Na~+ ions at (100) sites is decided. By analyzing the source of the Na~- displacement, the magnitude of the off-center displacement of F~- ion along <110> direction in NaBr crystal is determined as 0.45 A.