Nuclear Quadrupole Resonance of Li in Ferroelectric Compounds

Measurements have been made of the temperature dependence of the nuclear quadrupole coupling constant, $\frac{\mathrm{eQq}}{h}$, of Li in a number of ferroelectric compounds. The compounds discussed are LiN${\mathrm{H}}_4$ ${\mathrm{C}}_4$ ${\mathrm{H}}_4$ ${\mathrm{O}}_6$ ·${\mathrm{H}}_2$O, LiTl${\mathrm{C}}_4$ ${\mathrm{H}}_4$ ${\mathrm{O}}_6$·${\mathrm{H}}_2$O, LiTa${\mathrm{O}}_3$, LiNb${\mathrm{O}}_3$, and Li${\mathrm{N}}_2$ ${\mathrm{H}}_5$S${\mathrm{O}}_4$. Powdered samples were used in all cases except the first where single crystals were also measured and favorably compared with the powder results.