Ternary Li halides, such as ${\mathrm{Li}}_3{\text{Me}X}_6$ with, e.g., Me = In, Sc, Y and $X$ = Cl, Br, are the center of attention for battery applications, as these materials might serve as ionic electrolytes. To fulfill their function, such electrolytes must have an extraordinarily high ionic ${\mathrm{Li}}^{+}$ conductivity. Layer-structured ${\mathrm{Li}}_3{\mathrm{InCl}}_6$ represents such a candidate; however, understanding the origin of the rapid ${\mathrm{Li}}^{+}$ exchange processes needs further investigation. Spatially restricted, that is, low-dimensional particle diffusion, might offer an explanation for fast ion dynamics. It is, however, challenging to provide evidence for 2D diffusion at the atomic scale when dealing with polycrystalline powder samples. Here, we use purely diffusion-induced ${}^7\mathrm{Li}$ nuclear magnetic spin relaxation to detect anomalies that unambiguously show that 2D Li diffusion is chiefly responsible for the dynamic processes in a ${\mathrm{Li}}_3{\mathrm{InCl}}_6$ powder sample the present paper focusses on. The change of the spin-lattice relaxation rate $1/T_1$ as a function of inverse temperature $1/T$ passes through a rate peak that strictly follows asymmetric behavior. This feature is in excellent agreement with the model of P. M. Richards [Solid State Commun. 25, 1019 (1978)], suggesting a logarithmic spectral density function $J$ to fully describe 2D diffusion. Hence, ${\mathrm{Li}}_3{\mathrm{InCl}}_6$ belongs to the very rare examples for which 2D ${\mathrm{Li}}^{+}$ diffusion has been immaculately verified.

中文翻译：

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扩散诱导的核自旋弛豫揭示了 Li3InCl6 中的二维 Li+ 离子跳跃

三元锂卤化物，例如${李}_3{\text{我}X}_6$例如，Me = In、Sc、Y 和$X$= Cl、Br 是电池应用的关注焦点，因为这些材料可以用作离子电解质。为了实现其功能，此类电解质必须具有极高的离子度${李}^{+}$电导率。层结构${李}_3{\mathrm{氯化铟}}_6$代表这样的候选人；然而，了解快速的起源${李}^{+}$交换过程需要进一步研究。空间限制，即低维粒子扩散，可能为快离子动力学提供解释。然而，在处理多晶粉末样品时，在原子尺度上提供二维扩散的证据具有挑战性。在这里，我们使用纯粹的扩散诱导${}^7李$核磁自旋弛豫来检测异常，明确表明二维锂扩散是造成动态过程的主要原因${李}_3{\mathrm{氯化铟}}_6$本论文重点关注粉末样品。自旋晶格弛豫率的变化$1/{\mathrm{时间}}_1$作为温度倒数的函数$1/\mathrm{时间}$经过严格遵循不对称行为的速率峰值。这一特征与 P. M. Richards [ Solid State Commun.] 的模型非常吻合。 25 , 1019 (1978)]，提出对数谱密度函数$J$完整地描述二维扩散。因此，${李}_3{\mathrm{氯化铟}}_6$属于非常罕见的例子，对于 2D${李}^{+}$扩散已得到完美验证。