Hydrogen-Bond Network in Ferroelectric Lithium Trihydrogen Selenite, LiD₃(SeO₃)₂ by Deuteron Magnetic Resonance

Abstract

Deuteron magnetic resonance study is made of single crystals of LiD₃(SeO₃)₂ between −143°C and 110°C. The electric quadrupole coupling constant, eQq⁄h, the asymmetry parameter, η, and the directions of the principal axes of the field-gradient tensor are determined for each deuteron at room temperature. Three non-equivalent tensors are obtained corresponding to the three non-equivalent fairly strong hydrogen bonds determined by X-ray diffraction. The eQq⁄h and η are 107.8 kc/sec and 0.172 for D_a, 127.9 kc/sec and 0.154 for D_b, and 181.1 kc/sec and 0.101 for D_c, The hydrogen-bond network in LiD₃(SeO₃)₂ is determined. The atomic coordinates of deuterons are estimated from the results of the present DMR study. The field-gradient tensor of ⁷Li is also determined at room temperature. The values of eQq⁄h and η are 33.9 kc/sec and 0.593.