title: Studies of Fe-Cu microwires with nanogranular structure.
abstract: We report on the fabrication, and structural and magnetic characterization of Cu(63)Fe(37) microwires with granular structure produced by rapid quenching, using the Tailor-Ulitovsky method, from the immiscible alloys. X-ray diffraction study demonstrated that the structure consists of small (6-45 nm) crystallites of Cu and body centred cubic α-Fe. Magnetic properties have been measured in the range of 5-300 K using a SQUID (superconducting quantum interference device) magnetometer. The temperature dependences of the magnetization measured in a cooling regime when no external magnetic field is applied (zero-field cooling) and in the presence of the field (field cooling) show considerable difference below 20 K. This difference could be related to the presence of small α-Fe grains embedded in the Cu matrix. Those α-Fe grains appear to be blocked at temperatures below that at which the maximum of the magnetization is observed in the low temperature range. Significant magnetoresistance (about 7%) has been found in the samples studied. The shape of the observed dependences is typical of a giant magnetoresistance effect.
authors.affiliation: Department of Materials Physics, Faculty of Chemistry, PO Box 1072, 20080 San Sebastian, Spain. TAMAG Ibérica SL, Parque Tecnológico de Miramón, Paseo Mikeletegi 56, 1a Planta, 20009 San Sebastián, Spain.
authors.forename: A
authors.initials: A
authors.lastname: Zhukov
authors.forename: C
authors.initials: C
authors.lastname: García
authors.forename: J J
authors.initials: JJ
authors.lastname: Del Val
authors.forename: J
authors.initials: J
authors.lastname: Gonzalez
authors.forename: M
authors.initials: M
authors.lastname: Knobel
authors.forename: D
authors.initials: D
authors.lastname: Serantes
authors.forename: D
authors.initials: D
authors.lastname: Baldomir
authors.forename: V
authors.initials: V
authors.lastname: Zhukova