Cahill L S, Chapman R P, Britten J F, Goward G R
Department of Chemistry and Brockhouse Institute for Materials Research, McMaster University, 1280 Main Street W., Hamilton, ON, L8S 4M1 Canada.
J Phys Chem B. 2006 Apr 13;110(14):7171-7. doi: 10.1021/jp057015+.
High-resolution solid-state (7)Li NMR was used to characterize the structure and dynamics of lithium ion transport in monoclinic Li(3)V(2)(PO(4))(3). Under fast magic-angle spinning (MAS) conditions (25 kHz), three resonances are clearly resolved and assigned to the three unique crystallographic sites. This assignment is based on the Fermi-contact delocalization interaction between the unpaired d-electrons at the vanadium centers and the lithium ions. One-dimensional variable-temperature NMR and two-dimensional exchange spectroscopy (EXSY) are used to probe Li mobility between the three sites. Very fast exchange, on the microsecond time scale, was observed for the Li hopping processes. Activation energies are determined and correlated to structural properties including interatomic Li distances and Li-O bottleneck sizes.
高分辨率固态（7）Li NMR用于表征单斜Li(3)V(2)(PO(4))(3)中锂离子传输的结构和动力学。在快速魔角旋转（MAS）条件下（25 kHz），三个共振峰清晰分辨，并被指定为三个独特的晶体学位置。该指定基于钒中心未配对d电子与锂离子之间的费米接触离域相互作用。一维变温NMR和二维交换光谱（EXSY）用于探测三个位置之间的Li迁移率。对于Li跳跃过程，观察到在微秒时间尺度上的非常快速的交换。确定了活化能，并将其与包括原子间Li距离和Li-O瓶颈尺寸在内的结构性质相关联。
