Toshie Harazono

CHEMICAL SHIFT, CHEMICAL SHIFT ANISOTROPY, AND SPIN-LATTICE RELAXATION TIME IN 89Y-MAS AND -STATIC NMR OF YTTRIUM COMPOUNDS

The chemical shift, the range of chemical shift anisotropy, and the spin-lattice relaxation times (T1) in Y2O3, Y3Al5O12, and Y2O2S have been measured by solid state 89Y (nuclear spin 1/2)-MAS and -static NMR. The static NMR data and T1 are reported for the first time. The range of chemical shift anisotropy was 1500—2400 Hz. This range was influenced more by the nature of the atom bound to Y than by the coordination number or the crystallographic symmetry of Y. Very long T1 values were obtained for Y2O2S (6.61 h) and Y2O3 (3.92 h at 24d site and 3.81 h at 8b site). On the other hand, the T1 value (1.10 h) of Y3Al5O12 is much shorter compared with those of Y2O2S and Y2O3. The next-nearest neighboring atom of Y in Y3Al5O12 is identified as Al, which has the nuclear spin 5/2 of 100% natural abundance. The most likely origin of significantly shorter T1 of Y3Al5O12 is a dipole–dipole interaction between 89Y and 27Al.