Local electronic structure in a LiAlO_2 single crystal studied with ~7Li NMR spectroscopy and comparison with quantum chemical calculations

摘要

The local electronic structure of a γ-LiAlO_2 single crystal was investigated with ~7Li nuclear magnetic resonance measurements. We observed different sets of spectra which originate from the four crystallographically equivalent but magnetically inequivalent Li sites per unit cell. We find a coupling constant e~2qQ/h = 115.1 ± 0.6 kHz and an asymmetry parameter η = 0.69 ± 0.01. The directions of the principal axes of the electric field gradient tensor at the sites of the Li nuclei have also been determined. We compared these experimental results with quantum chemical calculations at density-functional level and found good agreement.