109Ag NMR and relazation mechanism in single crystal Ag β-alumina
Temperature dependence of 109Ag NMR spectrum and spin-lattice relaxation T1 was measured for a single crystal of Ag β-alumina (Ag1.17Al11O17.09) at external magnetic field of 4.7 T (9.3 MHz) and 9.4 T (18.6 MHz).Only a single spectrum peak is observed at room temperature, it reflects fast site exchange of Ag ions. The chemical shift of the peak position depends on the angle between c-axis and external field B0 From the angle dependence, the values of screening tensor are determined to be, δ(PAS)(xx)=δ(PAS)(yy)=-54.7 ppm, δ(PAS)(zz)=-212 ppm. The large difference between δ(PAS)(zz) and δ(PAS)(xx) indicates a strong interaction between Ag and surrounding oxygen. The relaxation mechanism is discussed using the Scalar Coupling (SC) model and Screening Tensor Fluctuation (STF) model. The field dependence of the T1, observed at 4.7 T and 9.4 T strongly supports the SC model. It suggests that there are strong correlations between Ag ions in β-alumina and it probably plays an important role to the high ionic conductivity.
Ag β-alumina 109Ag NMR Magnetic screening tensor Relazation mechanism
Yoshiki Iwai Osamu Kamishima Naoaki Kuwata Junichi Kawamura Takeshi Hattori
Institute for Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Department of Applied Physics, Tokyo University of Science, Tokyo 162-8601, Japan
国际会议
The 16th International Conference on Solid State Ionics(第十六届国际固态离子学会议)
上海
英文
862-866
2007-07-01（万方平台首次上网日期，不代表论文的发表时间）