2003/06/27 by D. A. Luzhbin, A. V. Pan, V. A. Komashko +4
Physics and Astronomy · #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.69.024506
published as Phys. Rev. B 69, 024506 (2004) · RevTex, 8 figures
arxiv created 2003/06/27 · arxiv updated 2009/11/30
Temperature dependences of the magnetic moment have been measured in YBa2Cu3O7-δ thin films over a wide magnetic field range (5 <= H <= 104 Oe). In these films a paramagnetic signal known as the paramagnetic Meissner effect has been observed. The experimental data in the films, which have strong pinning and high critical current densities (Jc ~ 2 × 106 A/cm2 at 77 K), are quantitatively shown to be highly consistent with the theoretical model proposed by Koshelev and Larkin [Phys. Rev. B 52, 13559 (1995)]. This finding indicates that the origin of the paramagnetic effect is ultimately associated with nucleation and inhomogeneous spatial redistribution of magnetic vortices in a sample which is cooled down in a magnetic field. It is also shown that the distribution of vortices is extremely sensitive to the interplay of film properties and the real experimental conditions of the measurements.