›› 2015, Vol. 24 ›› Issue (1): 17402-017402.doi: 10.1088/1674-1056/24/1/017402

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Field-dependent resistive transitions in Yba2Cu3O7-δ thin films: Influence of the pseudogap on vortex dynamics

S H Naqib, R S Islam   

  1. Department of Physics, University of Rajshahi, Rajshahi-6205, Bangladesh
  • 收稿日期:2014-06-05 修回日期:2014-11-25 出版日期:2015-01-05 发布日期:2015-01-05

Field-dependent resistive transitions in Yba2Cu3O7-δ thin films: Influence of the pseudogap on vortex dynamics

S H Naqib, R S Islam   

  1. Department of Physics, University of Rajshahi, Rajshahi-6205, Bangladesh
  • Received:2014-06-05 Revised:2014-11-25 Online:2015-01-05 Published:2015-01-05
  • Contact: S H Naqib E-mail:salehnaqib@yahoo.com

摘要: The nature of resistive transition of high-quality crystalline thin films of Yba2Cu3O7-δ has been studied under magnetic fields (H) applied along the c direction over a wide range of doped holes, p, in the CuO2 planes. The field- and temperature-dependent in-plane resistivity, ρab(T,H), has been analyzed within the thermally assisted flux-flow (TAFF) formalism. The flux activation energy, U(T,H), has been extracted from this analysis. The low-T part of the ρab(T,H) data can be described by an activation energy having the functional form of U(T,H) = (1-t)m(H0/H), where t = T/Tc (reduced temperature), and H0 is a field scale that primarily determines the magnitude of U(T,H). The temperature exponent, m, shows a systematic variation with p, whereas the field exponent, β, is insensitive to the p values and is close to unity. The H0, on the other hand, changes rapidly as p is varied. U(T,H) is linked to the pinning potential and consequently on the superconducting condensation energy. Since the normal state pseudogap directly affects superconducting condensation energy, a clear correspondence between H0 and the PG energy scale, εg, is found. Possible implications of these results are discussed.

关键词: Y123 superconductors, thermally assisted flux-flow model, activation energy, pseudogap

Abstract: The nature of resistive transition of high-quality crystalline thin films of Yba2Cu3O7-δ has been studied under magnetic fields (H) applied along the c direction over a wide range of doped holes, p, in the CuO2 planes. The field- and temperature-dependent in-plane resistivity, ρab(T,H), has been analyzed within the thermally assisted flux-flow (TAFF) formalism. The flux activation energy, U(T,H), has been extracted from this analysis. The low-T part of the ρab(T,H) data can be described by an activation energy having the functional form of U(T,H) = (1-t)m(H0/H), where t = T/Tc (reduced temperature), and H0 is a field scale that primarily determines the magnitude of U(T,H). The temperature exponent, m, shows a systematic variation with p, whereas the field exponent, β, is insensitive to the p values and is close to unity. The H0, on the other hand, changes rapidly as p is varied. U(T,H) is linked to the pinning potential and consequently on the superconducting condensation energy. Since the normal state pseudogap directly affects superconducting condensation energy, a clear correspondence between H0 and the PG energy scale, εg, is found. Possible implications of these results are discussed.

Key words: Y123 superconductors, thermally assisted flux-flow model, activation energy, pseudogap

中图分类号:  (Vortex phases (includes vortex lattices, vortex liquids, and vortex glasses))

  • 74.25.Uv
74.62.Dh (Effects of crystal defects, doping and substitution) 74.72.Ek (Electron-doped) 74.25.Dw (Superconductivity phase diagrams)