Tetrahedral structure in LiKSO4 crystals studied by 7Li and 39K NMR

The Li-7 and K-39 nuclear magnetic resonances in a LiKSO4 single crystal grown by the slow evaporation method were investigated by employing an NMR spectrometer. From the experimental data, the quadrupole coupling constant and asymmetry parameter were determined at room temperature. The principal axes corresponding to the largest principal value of the Li-7 and K-39 EFG tensors were parallel to the hexagonal c-axis. This direction was determined to be the Z-axis of the EFG tensor. The EFG tensor of Li-7 and K-39 was found to be non-axially symmetric; the lithium ion is surrounded by oxygen atoms located at a slightly distorted tetrahedron, and the resultant coordinating potassium ion was enclosed by the oxygen atoms located at nine distorted tetrahedra. (C) 2001 Elsevier Science Ltd. All rights reserved.