We study ionic transport in nano- and microcrystalline (1 - x)Li 2O:xB2O3 composites using standard impedance spectroscopy. In the nanocrystalline samples (average grain size of about 20 nm), the ionic conductivity σdc increases with increasing content x of B2O3 up to a maximum at x ≈ 0.5. Above x ≈ 0.92, σdc vanishes. By contrast, in the microcrystalline samples (grain size about 10 μm), σdc decreases monotonically with x and vanishes above x ≈ 0.55. We can explain this strikingly different behavior by a percolation model that assumes an enhanced conductivity at the interfaces between insulating and conducting phases in both materials and explicitly takes into account the different grain sizes. © 2000 The American Physical Society.
Indris, S., Heitjans, P., Roman, H., Bunde, A. (2000). Nanocrystalline versus microcrystalline Lo2O:B2O 3 composites: Anomalous ionic conductivities and percolation theory. PHYSICAL REVIEW LETTERS, 84(13), 2889-2892 [10.1103/PhysRevLett.84.2889].
Nanocrystalline versus microcrystalline Lo2O:B2O 3 composites: Anomalous ionic conductivities and percolation theory
Roman H. E.;
2000
Abstract
We study ionic transport in nano- and microcrystalline (1 - x)Li 2O:xB2O3 composites using standard impedance spectroscopy. In the nanocrystalline samples (average grain size of about 20 nm), the ionic conductivity σdc increases with increasing content x of B2O3 up to a maximum at x ≈ 0.5. Above x ≈ 0.92, σdc vanishes. By contrast, in the microcrystalline samples (grain size about 10 μm), σdc decreases monotonically with x and vanishes above x ≈ 0.55. We can explain this strikingly different behavior by a percolation model that assumes an enhanced conductivity at the interfaces between insulating and conducting phases in both materials and explicitly takes into account the different grain sizes. © 2000 The American Physical Society.
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