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Digital speckle pattern interferometry has been used to detect inhomogeneous heating in YBa2Cu3O7-δ coated conductors. The analysis was performed in a sample with a controlled defect, which causes a significant local reduction in the critical current value, Ic. The experiments, which were performed with the sample surrounded by nitrogen vapor, have shown that the location of the initial hot spot leading to the complete transition to the normal state of the conductor (quench) is strongly dependent on the sample cooling configuration. When the sample is mainly cooled by gas convection, the quench always starts in the low-Ic region, while for improved cooling configurations the initial hot spot does not always coincide with this region. The results have been compared with those obtained by direct electric field measurements along the sample in nitrogen vapor and liquid. [ABSTRACT FROM AUTHOR]

Digital speckle pattern interferometry is used for detecting inhomogeneous heating in Y[Ba.sub.2][Cu.sub.3][O.sub.7-[delta]] coated conductors. The experiments have shown that the location of the initial hot spot leading to the complete transition to the normal state of the conductor is dependent on the sample cooling configuration and the results are compared with those obtained by direct electric field measurements along the sample in nitrogen vapor and liquid.

Discusses a study which determined the crystal structure and magnetic properties of the layered compound Co(HPO[sub3]) H[sub2]O. Formation and refinement of the structure; Description of the structure; Characterization of the magnetic properties of the sample.