Ionic conduction in solids

In an ideal ionic crystal, all ions are held rigidly in the lattice sites, where they perform only thermal vibratory motion. Transfer of an ion between sites under the effect of electrostatic fields (migration) or concentration gradients (diffusion) is not possible in such a crystal. Initially, therefore, the phenomenon of ionic conduction in solid ionic crystals was not understood. 

The theoretical treatment of ionic conductivity in solids is very similar to that of diffusion, the main difference is the superimposition of the potential field upon the potential barrier to migration (Fig. 3). 

J.B. Goodenough, Fast ionic conduction in solids. Proc. Roy. Soc. (London), A393 (1984) 214-234. 

The ionic transport in solids is attributed to the hopping of ionic carriers between the equivalent positions in the crystal lattice. This mechanism is known as lattice diffusion and depends on the jumping distance and frequency of moved ions. The understanding of the influence of these factors on the ionic conductivity is very important for the development of material with enhanced ionic transport. The question of what is the limit of ionic conductivity in solids will be addressed by analyzing the ionic transport in cubic stabilized zirconia systems with different acceptor dopants. 

History of Ionic Conductivity in Solid Polymer Electrolytes... 

Certain crystallographic and glass stractrrres allow rather easy motion of iotrs, in both MIECs and SEs. For ionic conduction in solids to occtn, iotrs have to move through a rather dense matrix (whether crystalline or amorphous) consisting of ionic species of comparable size. To enable this, three conditiotrs must be fulfilled (a) an empty site exists in the forward direction, into which a corrducting ion can move (b) the propagation of the ion... 

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