Scaling of thin-film Nd{sub 1.85}Ce{sub 0.15}CuO{sub 4{minus}{ital y}} resistivity-current isotherms at low fields: Implications for vortex phase transitions and universality
- Department of Physics, Oregon State University, Corvallis, Oregon 97331-6507 (United States)
- National Institute of Standards and Technology, Gaithersburg, Maryland 20899 (United States)
- Center for Superconductivity Research, Department of Physics, University of Maryland, College Park, Maryland 20742 (United States)
We have investigated a second-order phase transition of the vortex lattice in thin-film Nd{sub 1.85}Ce{sub 0.15}CuO{sub 4{minus}{ital y}} from 1 mT to 1 T applied magnetic fields. The dc resistivity-current density data for each field exhibit critical scaling consistent with a second-order vortex-liquid to vortex-solid phase transition. The high-field data support the vortex-glass model and have the same critical exponents as thin-film YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}}. At low fields we observe a change in the critical exponents and universal functions. The critical regime diminishes as the field is decreased but remains nonzero even at 1 mT. These results suggest that the universality class of the transition changes at low fields.
- OSTI ID:
- 54931
- Journal Information:
- Physical Review, B: Condensed Matter, Vol. 51, Issue 21; Other Information: PBD: 1 Jun 1995
- Country of Publication:
- United States
- Language:
- English
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