Cardwell, DA and Jones, AR and Ingle, NJC and Campbell, AM and Button, TW and Alford, NM and Wellhofer, F and Abell, JS (1994) Investigation of critical state in melt processed YBa2Cu3O7-δ thick films. Cryogenics, 34. pp. 671-677. ISSN 0011-2275Full text not available from this repository.
The magnetic moment of square planar melt processed YBa2Cu3O7-δ thick films is observed to scale with the cube of the sample width at 4.2 K, suggesting that current flow on the length scale of the film determines its magnetization at this temperature. A well-defined discontinuity in slope in the scaling data at a sample width corresponding to the average grain size (≈2 mm) implies the coexistence of distinct intra- and inter-grain critical current densities of 1.1 × 105 A cm-2 and 0.4 × 105 A cm-2 at 1 T and 4.2 K. The presence of a critical state in the films at 4.2 T is confirmed by removing the central section from a specimen. The observed change in magnetic moment is in excellent agreement with theory for fields greater than ≈2 T. A critical state is not observed at 77 K which suggests that the grains are only weakly coupled at the higher temperature.
|Uncontrolled Keywords:||critical current density critical state granularity thick films|
|Divisions:||Div C > Materials Engineering|
|Depositing User:||Cron Job|
|Date Deposited:||07 Mar 2014 11:40|
|Last Modified:||26 Jan 2015 03:24|