Anomalous Magnetic Field Dependence of the Thermodynamic Transition Line in the Isotropic Superconductor <span class="aps-inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><mo>(</mo><mi>K</mi><mo>,</mo><mi>B</mi><mi>a</mi><mo>)</mo><mrow><msub><mrow><mi>BiO</mi></mrow><mrow><mn>3</mn></mrow></msub></mrow></math></span>

S. Blanchard; T. Klein; J. Marcus; I. Joumard; A. Sulpice; P. Szabo; P. Samuely; A. G. M. Jansen; C. Marcenat

doi:10.1103/PhysRevLett.88.177201

Anomalous Magnetic Field Dependence of the Thermodynamic Transition Line in the Isotropic Superconductor $(K, B a) {BiO}_{3}$

S. Blanchard, T. Klein, J. Marcus, I. Joumard, A. Sulpice, P. Szabo, P. Samuely, A. G. M. Jansen, and C. Marcenat

Phys. Rev. Lett. 88, 177201 – Published 11 April 2002

Abstract

Thermodynamic (specific heat, reversible magnetization, tunneling spectroscopy) and transport measurements have been performed on high quality $(K, Ba) {BiO}_{3}$ single crystals. The temperature dependence of the magnetic field $H_{C_{p}}$ corresponding to the onset of the specific heat anomaly presents a clear positive curvature. $H_{C_{p}}$ is significantly smaller than the field $H_{Δ}$ for which the superconducting gap vanishes but is closely related to the irreversibility line deduced from transport data. Moreover, the temperature dependence of the reversible magnetization presents a strong deviation from the Ginzburg-Landau theory emphasizing the peculiar nature of the superconducting transition in this material.

Received 20 September 2001

DOI:https://doi.org/10.1103/PhysRevLett.88.177201

Authors & Affiliations

S. Blanchard¹, T. Klein^1,2, J. Marcus¹, I. Joumard¹, A. Sulpice³, P. Szabo^2,4, P. Samuely⁴, A. G. M. Jansen⁵, and C. Marcenat⁶

¹Laboratoire d'Etudes des Propriétés Electroniques des Solides, Centre National de la Recherche Scientifique, BP 166, F-38042 Grenoble Cedex 9,France
²University Joseph Fourier, BP 53, F-38041 Grenoble Cedex 9, France
³Centre de Recherche sur les Très Basses Températures, Centre National de la Recherche Scientifique, BP 166, 38042 Grenoble Cedex 9, France
⁴Institute of Experimental Physics, Slovak Academy of Sciences, SK-04353 Košice, Slovakia
⁵Grenoble High Magnetic Field Laboratory, Max-Planck-Institut für Festkörperforschung and Centre National de la Recherche Scientifique, BP 166, F-38042 Grenoble Cedex 9, France
⁶Commissariat à l'Energie Atomique–Grenoble, Département de Recherche Fondamentale sur la Matière Condensée, SPSMS, 17 rue des Martyrs, F-38054 Grenoble Cedex 9, France