Thermal Fluctuations in the High-Temperature Superconductor CaLaBaCu3O7–δ

✍ Scribed by D.A. Landínez Téllez; J. Roa-Rojas; J. Albino Aguiar; J.M. Calero

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 87 KB
• Volume: 220
• Category: Article
• ISSN: 0370-1972
• DOI: 10.1002/1521-3951(200007)220:1<545::aid-pssb545>3.0.co;2-l

✦ Synopsis

Magnetization measurements on a polycrystal of CaLaBaCu 3 O 7Àd in high magnetic fields (20 to 50 kOe) are reported. The sample has a zero-field transition temperature T c0 77 K and a transition width of 2.0 K. The results show large fluctuation effects, which can be explained by Ginzburg-Landau fluctuation theory for a two-dimensional system. The magnetization displays good scaling behavior as a function of T À T c H = TH 1=2 . The experimental data were fitted by using a theoretical model based in the lowest Landau levels approximation, showing good agreement. We also analyze fluctuation effects in conductivity measurements at zero magnetic field.