Spatial distribution of lithium ions in glasses studied by 7Li{6Li} spin echo double resonance

摘要: This manuscript introduces 7Li{6Li} spin echo double resonance (SEDOR) spectroscopy as a novel approach for studying the spatial distribution of lithium ions in solid electrolytes. Theoretical simulations using density operator theory well experimental validation on model compound carbonate reveal that this method affords selective measurement 7Li–6Li heteronuclear dipole–dipole couplings. Dipolar second moments characterizing internuclear lithium–lithium interactions have been measured silicate (Li2O)x(SiO2)1−x, (0.1 ≤ x ≤ 0.4) and borate (Li2O)x(B2O3)1−x, 0.3) glasses. The results indicate distributions these two glass systems are decidedly different. In system, give clear evidence strong cation clustering x ≤ 0.3, providing quantitative support previously proposed one-dimensional channel structure. contrast, cations seem to be more or less randomly distributed. Nevertheless, an observed superlinear dependence M2(7Li–6Li) function ion concentration indicates subtle changes arrangement principles, which discussed relation ring structure