Why pinning by surface irregularities can explain the peak effect in transport properties and neutron diffraction results in NbSe2 and Bi-2212 crystals?

Pramana

D Plessis¹  Antoine Ruyter⁵  Charles Simon1⁶  Shobo Bhattacharya⁷  Patrice Mathieu⁴  Annie Brûlet²  Alain Pautrat⁶  M J Higgins³  Christophe Goupil⁶  Joseph Scola⁶ 

[1] CEA/DMAT - B.P. 16 Le Ripault-37260 MONTS France$$;Laboratoire Léon Brillouin, Saclay, France$$;NEC, Princeton, USA$$;Laboratoire Pierre Aigrain ENS Paris, France$$;LEMA, UMR CNRS CEA Université de Tours, F 37200 Tours, France$$;Laboratoire CRISMAT, CNRS-ENSICAEN, F14050 Caen, France$$;Tata Institute of Fundamental Research, Mumbai 400 005, India$$

关键词: Vortex pinning;    neutron scattering;    critical current.;   

DOI  :  

学科分类：物理（综合）

来源: Indian Academy of Sciences

【 摘 要 】

The existence of a peak effect in transport properties (a maximum of the critical current as function of magnetic field) is a well-known but still intriguing feature of Type II superconductors such as NbSe2 and Bi-2212. Using a model of pinning by surface irregularities in anisotropic superconductors, we have developed a calculation of the critical current which allows estimating quantitatively the critical current in both the high critical current phase and the low critical current phase. The only adjustable parameter of this model is the angle of the vortices at the surface. The agreement between the measurements and the model is really very impressive. In this framework, the anomalous dynamical properties close to the peak effect is due to coexistence of two different vortex states with different critical currents. Recent neutron diffraction data in NbSe2 crystals in the presence of transport current support this point of view.

【 授权许可】

Unknown