NMR Study of Ferroelectric LiNbO3 and LiTaO3. I

A study of the 7Li nuclear magnetic resonance in a LiNbO3 single crystal is made and the electric field gradient at the lithium site is determined. Electric-field-gradient calculations indicate that the net charge on the niobium is +1.59 while that on the oxygens is −0.86. This shows that the niobate ion is predominately covalently bonded. The 93Nb resonance in a LiNbO3 single crystal and the 7Li resonance in powder samples of LiNbO3–LiTaO3 solid solutions are reported.