'Illusional' nano-size effect due to artifacts of in-plane conductivity measurements of ultra-thin films

High-Temperature Energy Materials Center, Korea Institute of Science and Technology, Seoul, Republic of Korea.
Physical Chemistry Chemical Physics (Impact Factor: 4.2). 02/2011; 13(13):6133-7. DOI: 10.1039/c0cp02673e
Source: PubMed

ABSTRACT The nano-size effect, which indicates a drastic increase in conductivity in solid electrolyte materials of nano-scale microstructures, has drawn substantial attention in various research fields including in the field of solid oxide fuel cells (SOFCs). However, especially in the cases of the conductivity of ultra-thin films measured in an in-plane configuration, it is highly possible that the 'apparent' conductivity increase originates from electrical current flowing through other conduction paths than the thin film. As a systematic study to interrogate those measurement artifacts, we report various sources of electrical current leaks regarding in-plane conductivity measurements, specifically insulators in the measurement set-up. We have observed a 'great conductivity increase' up to an order of magnitude at a very thin thickness of a single layer yttria-stabilized zirconia (YSZ) film in a set-up with an intentional artifact current flow source. Here we propose that the nano-size effect, reported to appear in ultra-thin single layer YSZ, can be a result of misinterpretation.

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