Grain boundary transport behavior

The material behaviors considered will include linear elasticity plus linear or nonlinear creep behavior. The nonlinear case will be restricted to power-law rheologies. In some cases the elasticity will be idealized as rigid. In ceramics, it is commonly the case that creep occurs by mass transport on the grain boundaries.1 This usually leads to a linear rheology. In the models considered,... 

Clearly, since the Cu02 planes, which play an essential role in the superconducting transport, are disrupted across the (010)(001) boundaries, they are expected to show weak-link behavior. However, since the Cu02 planes are continuous across (013)(013) boundaries, the latter may provide good supercurrent conducting paths across the 90° [100] tilt grain boundaries, resulting possibly in weak-link free behavior [10.43]. Measurements across individual... 

This work clearly demonstrated that it is important to establish direct correlations between microstructure and transport properties of grain boundary junctions. At this point, both the complex and varied structures of grain boundaries that have been found and the extremely complicated transport behavior, present considerable challenges concerning the development of models for the connection between structure and transport properties. However, it is clear that progress in this field is directly dependent on our ability to develop such models. 

This behavior illustrates the potential to enhanee the ionic conductivity when electrical transport involves interfacial effects. The present estimates of the interfacial conductivity contribution in epitaxial YSZ thin films correlate well with the enhancement in grain boundary oxygen diffusivity obtained by tracer diffusion and secondary ion mass spectroscopy (SIMS)... 

One dimensional geometry Because the scale of phase separation in the junction is small compared to the device size, an effective medium approach is often applied, and one-dimensional symmetry assumed. This means neglecting the effect of local electric fields at the interface, and differences in behavior between electrons or ions that are near or further from the interface or grain boundaries. The effect of electrolyte on electron transport can be included through an effective diffusion coefficient. 

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