离子导体LiCl(Al2O3)的核磁共振研究

本文报道了含分散第二相粒子的离子导体LiCl(或LiI)中⁷Li核磁共振的观测结果,测量了⁷Li核磁共振吸收谱线的线宽和自旋-晶格弛豫时间(T₁)。实验发现,在LiCl(Al₂O₃)中,⁷Li的核磁共振吸收谱线上叠加了一小峰,且随第二相粒子的类型、含量和温度而变化。⁷Li核磁共振信号的信噪比显著提高,自旋-晶格弛豫时间变短,且也随第二相粒子的类型、含量和温度而变化。结果表明,离子电导率的提高和附加小峰的出现都是由第二相粒子引起的,从而提出:靠近第二相粒子的LiCl界面附近的空间电荷区中高的离子传导是离子电导率提高和附加小峰出现的可能机理。 关键词：

7Li NMR INVESTIGATIONS IN LiCl WITH DSPP

In order to understand the mechanism of the ionic conduetivity enhancement in LiCl (or LiI) containing dispersed second-phase particles (DSPP), we have performed ⁷Li NMR investigations on both line width and spin-lattice relaxation time (T₁) at 35 MHz in temperature range of 173-483 K. An additional peak was observed to overlap the resonance absorption line. The signal-to-noise ratio was obviously increased while T₁ decreased. The profile of this peak changes with type and content of DSPP and temperature. It is concluded that the ionic eonductivity enhancement and the appearing of the additional peak are both given rise by the DSPP of submicron size. The high conduction in the space charge region near the interface between LiCl and DSPP is suggested as a possible mechanism for the ionic conductivity enhancement and the appearing of the additional peak.