NMR study on electronic and magnetic state in RTiO(3) (R=La,Y)

The electronic and magnetic states in perovskite titanates, RTiO(3) have been investigated microscopically by NMR. In the ferromagnetically-ordered state of YTiO3, (T-c=25K) there exist two magnetically-inequivalent Ti sites with slightly different internal fields, H-int, corresponding to the reduced Ti moments of 0.69 and 0.76 mu(B). H-int of Y-89 is -10.3 kOe in YTiO3, while H-int at the La-139 sire is canceled out in the antiferromagnetic LaTiO3. Nuclear spin-lattice relaxation time, TI, of Y-89 increase drastically with decreasing temperature below similar to 60K where the ferromagnetic alignment of Ti moments induced by external filed seems to grow up. T-1 of La-139 in Sr-doped LaTiO3 obeys the Korringa relation, T1T=const. of which value increases critically on approaching the Mott insulator-metal transition.