Nuclear Magnetic Resonance Study of the Phase Transition in Strontium Titanate

Abstract

The nuclear magnetic resonances of Sr87, Ti47, and Ti49 in a single crystal of SrTiO3 have been studied in the vicinity of the phase transition at 110°K. The Sr87 resonance exhibited line broadening and a gradual decrease in amplitude below 110°K. This is attributed to quadrupole interactions arising from a noncubic crystalline field and is in agreement with electron paramagnetic resonance experiments. No change in the titanium resonance was observed upon cooling the crystal to the lowest available temperature of 95°K. From estimates of the quadrupole coupling constants, the results suggest that the ionic displacements are small and very little distortion of the titanium—oxygen octahedra occurs during the structural phase transition in SrTiO3.