题 目:Magnetic and superconducting properties of lead/cobolt superconductor/ferromagnet nanocomposites
报告人:Dr. Yutao Xing
Centro Brasileiro de Pesquisas Físicas
时 间:1月13日(周三)9:15-10:15
地 点:李薰楼468会议室
报告摘要:Superconductor (SC)/ferromagnet (FM) nanocomposites made from FM Co clusters (mean diameter 4.5 nm) embedded in a SC Pb film (thickness: 100nm) have been prepared by the co-deposition of well-defined, in-beam prepared Co clusters and Pb atoms. Transport properties have been measured in-situ, magnetic properties ex-situ in a SQUID magnetometer. The resistivity data of the films, annealed at 300 K, indicate the occurrence of spontaneous vortex phases in the absence of an external magnetic field and any macroscopic magnetization (the orientation of the Co cluster magnetic moments μ without external magnetic field is completely random). The magnetic data give further evidence for the spontaneous vortex formation due to the finding that (i) the magnetization M of the films below the superconducting transition at Tc depends on the orientation of μ if these have been oriented in an external field before cooling down the sample below Tc and (ii) the magnitude of M exceeds that of the saturation magnetization of the Co clusters.
Welcome to attend!