Nuclear magnetic resonance study of Li-7 and Cs-133 in a nonlinear optical CsLiB6O10 single crystal

Abstract

The rotation patterns of the nuclear magnetic resonance of Li-7 (I = 3/2) and Cs-133 (I = 7/2) in a nonlinear optical CsLiB6O10 single crystal were measured in two mutually perpendicular crystal planes. From these results, the quadrupole coupling constants and the asymmetry parameters were determined at room temperature. For Li-7, e(2)qQ/h = 180 +/- 2 kHz and eta = 0, and for Cs-133, e(2)qQ/h = 574 +/- 2 kHz and eta = 0. The electric field gradient (EFG) tensors of Li-7 and Cs-133 are axially symmetric: V-XX = V-YY and V-ZZ is along the four-fold symmetry around the c-axis. Both the Li ions, which are surrounded by four oxygen atoms, and the Cs ions, which are surrounded by eight oxygen atoms have high symmetry. The principal axes of the EFG tensors of both Li-7 and Cs-133 are parallel to the crystallographic axis. The temperature dependence of e(2)qQ/h for Li-7 and Cs-133 is explained with a single torsional frequency of the Li-O and the Cs-O ions about the Z-axis of the EEG tensor. (C) 2002 Elsevier Science Ltd. All rights reserved.