2006/12/15 by S. Sergeenkov, A. J. C. Lanfredi, Alexandre J. C. Lanfredi +2 · 1 citation
Physics and Astronomy · #Advanced Condensed Matter Physics #Physics of Superconductivity and Magnetism #Theoretical and Computational Physics #cond-mat.mtrl-sci #cond-mat.supr-con
paper · pdf · doi:10.1063/1.2402969
published as J. Appl. Phys. 100, 123903 (2006)
openalex publication_date 2006/12/15 · arxiv created 2007/01/19 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
ac magnetic susceptibilities of electron-doped Pr1.85Ce0.15CuO4 (PCCO) and Sm1.85Ce0.15CuO4 (SCCO) granular thin films have been measured as a function of temperature and magnetic-field strength. Depending on the level of homogeneity of our films, two different types of the irreversibility line (IL), Tirr≡Tp(H), defined as the intergrain-loss peak temperature in the imaginary part of the susceptibility and obeying the law 1−Tp∕TC∝Hq, have been found. Namely, more homogeneous PCCO films (with a grain size of the order of 2μm) are best-fitted with q=2∕3 while less homogeneous SCCO films (with a grain size of the order of 500nm) follow the IL law with q=1. The obtained results are described via the critical-state model taking into account the low-field grain-boundary pinning. The extracted pinning-force densities in more granular SCCO films turn out to be four times larger than their counterparts in less granular PCCO films.