ION DYNAMICS AND MANY-BODY EFFECT BETWEEN MOBILE IONS IN SUPER IONIC CONDUCTOR

测定了agss -氧化铝的偏振拉曼光谱。通过拉曼声子特征值的非线性最小二乘拟合和基于刚性离子模型的动态矩阵计算确定了原子间势。利用agss -氧化铝模型晶体进行了分子动力学（MD）计算，以了解离子快速扩散的多体效应。我们提出了对超离子传导的新认识，即离子传递的活化能由两种元素组成；一个“静态”活化能和一个“动态”活化能。静态活化能是各种结构构型在平衡状态下的平均能差的代价。动态激活能是由跳跃过程引起的结构松弛所需要的额外能量。

Polarized Raman spectra of Agss-alumina have been measured. The interatomic potentials were determined by a non-linear least square fitting between phonon eigenvalues from Raman and dynamical matrix calculation based on a Rigid-Ion model. A molecular dynamics(MD) calculation has been carried out using the model crystal of Agss-alumina to understand the many-body effects for the fast ionic diffusion. We proposed a new insight into the super ionic conduction, that is, the activation energy for the ionic transport is composed of two kinds of elements ; a "static" activation energy and a "dynamic" one. The static activation energy is the cost of averaged energy difference in the various structural configurations at equilibrium state. The dynamic activation energy is an additional energy required for the structural relaxation induced by the jump process.