Upper critical field of Ba{sub 1-x}K{sub x}BiO{sub 3} measured by magnetotunneling spectroscopy

Journal Article · Sun Dec 01 04:00:00 EST 1996 · Journal of Low Temperature Physics

DOI:https://doi.org/10.1007/BF00753869· OSTI ID:443652

Samuely, P; Szabo, P ^[1]; Jansen, A G.M.; Wyder, P ^[2]

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1. Institute of Experimental Physics, Kosice (Slovakia)
2. Grenoble High Magnetic Field Lab. (France); and others

In contrast to the conventional picture the upper critical fields measured by magnetoresistance in high-T{sub c} superconductors including cubic Ba{sub 1{minus}x}K{sub x}BiO{sub 3} reveal a positive curvature in the temperature dependence. Several explanations have been proposed, but in magnetoresistance measurements flux-flow phenomena can play a role. The authors address the problem by tunneling Spectroscopy, where they measure the superconducting density of states. The elastic tunneling current has been measured in the whole temperature and magnetic-field range up to the critical values. The obtained H{sub c2} (T) dependence is in agreement with the Werthamer-Helfand-Hohenberg prediction.

• Sponsoring Organization: USDOE
• OSTI ID: 443652
• Report Number(s): CONF-960808--; CNN: Grant CIPA-CT93-0183; Contract 2/1357/94
• Journal Information: Journal of Low Temperature Physics, Journal Name: Journal of Low Temperature Physics Journal Issue: 5-6 Vol. 105; ISSN JLTPAC; ISSN 0022-2291
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BARIUM OXIDES
BISMUTH OXIDES
CRITICAL FIELD
HIGH-TC SUPERCONDUCTORS
MAGNETORESISTANCE
POTASSIUM OXIDES
TEMPERATURE DEPENDENCE