2008/05/09 by Akiyasu Yamamoto, A. Yamamoto, Jianyi Jiang +24 · 2 citations
Materials Science · Physics and Astronomy · #Iron-based superconductors research #Physics of Superconductivity and Magnetism #Rare-earth and actinide compounds #cond-mat.mtrl-sci #cond-mat.supr-con
paper · pdf · doi:10.1063/1.2952195
published as Appl. Phys. Lett. vol. 92, no. 252501 (2008) · 3 pages, 6 figures
arxiv created 2008/05/09 · openalex publication_date 2008/06/23 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
The recently discovered oxypnictide superconductors are layered, low carrier density compounds with many similarities to the high-Tc cuprates. An important question is whether they also exhibit weak-coupling across randomly oriented grain boundaries. In this work we show considerable evidence for such weak coupling by study of the dependence of magnetization in bulk and powdered samples. Bulk sample magnetization curves show very little hysteresis while remanent magnetization shows almost no sample size dependence, even after powdering. We conclude that these samples exhibit substantial electromagnetic granularity on a scale approximating the grain size, though we cannot yet determine whether this is intrinsic or extrinsic.