Presence of3dQuadrupole Moment inLaTiO3Studied byTi47,49NMR

${}^{47,49}\mathrm{T}\mathrm{i}$ NMR spectra of ${\mathrm{L}\mathrm{a}\mathrm{T}\mathrm{i}\mathrm{O}}_3$ are reexamined and the orbital state of this compound is discussed. The NMR spectra of ${\mathrm{L}\mathrm{a}\mathrm{T}\mathrm{i}\mathrm{O}}_3$ taken at 1.5 K under zero external field indicate a large nuclear quadrupole splitting. This splitting is ascribed to the presence of the rather large quadrupole moment of $3d$ electrons at Ti sites, suggesting that the orbital liquid model proposed for ${\mathrm{L}\mathrm{a}\mathrm{T}\mathrm{i}\mathrm{O}}_3$ is inappropriate. The NMR spectra are well explained by the orbital ordering model expressed approximately as $1/\sqrt{3}(d_{xy}+d_{yz}+d_{zx})$ originating from a crystal field effect. It is also shown that most of the orbital moment is quenched.