Current transport across grain boundaries in TlBa/sub 2/Ca/sub 2/Cu/sub 3/O/sub x/ thick polycrystalline films and YBa/sub 2/Cu/sub 3/O/sub 7/ step edges
- Resource Type
- Periodical
- Authors
- Hettinger, J.D.; Kim, D.H.; Miller, D.J.; Hu, J.G.; Gray, K.E.; Sharping, J.E.; Daly, K.; Pettiette-Hall, C.; Tkaczyk, J.E.; Deluca, J.
- Source
- IEEE Transactions on Applied Superconductivity IEEE Trans. Appl. Supercond. Applied Superconductivity, IEEE Transactions on. 3(1):1211-1214 Mar, 1993
- Subject
- Fields, Waves and Electromagnetics
Engineered Materials, Dielectrics and Plasmas
Grain boundaries
Magnetic field measurement
Temperature dependence
Magnetic fields
Performance evaluation
Epitaxial growth
Substrates
Current density
Superconducting epitaxial layers
Josephson junctions
- Language
- ISSN
- 1051-8223
1558-2515
2378-7074
The authors have performed transport measurements in magnetic fields (H//c) up to 10 T on a series of YBa/sub 2/Cu/sub 3/O/sub 7/ grain boundaries induced by epitaxial growth on a substrate containing a series of step edges. An activation energy which goes as U(T) approximately (1-t) is found. Electric field versus current density curves taken at a constant temperature while varying the magnetic field allows a determination of the magnetic field dependence of the activation energy using the Ambagaokar-Halperin model. These values agree with results extracted from the resistive transitions. Similar characterizations of a sample of TlBa/sub 2/Ca/sub 2/Cu/sub 3/O/sub x/ are also presented. The temperature dependence of the activation energy for this system may be represented as U(T) approximately (1-t)/sup 2/, suggesting that the grain boundaries behave as SNS (superconducting-normal-superconducting) junctions.ETX