Imaging of electrical inhomogeneities in YBa2Cu3O7−x thin-film structures by room-temperature laser scanning microscopy

✍ Scribed by Yu.Ya. Divin; P.M. Shadrin

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 670 KB
• Volume: 232
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(94)90784-6

✦ Synopsis

Imaging of local electrical inhomogeneities in YBa2Cu307_ x thin films and grain-boundary junctions was demonstrated at room temperature. The spatial distributions of the voltage response of the samples to the focused laser beam were measured with and without bias current through the samples. High-contrast electrical images consisting of 512 × 512 points with 8 bit signal resolution and a spatial resolution of up to 1 lam were obtained for all YBa2Cu307_x samples under study. The zero-bias response was shown to reveal the grain-boundary regions in the samples and might be explained by thermoelectric effects. The response proportional to the current bias was shown to be due to the bolometric effect in the material itself and this response can be used to study the inhomogeneities in grain composition.