title: Evolution of the magnetic properties of Co10Cu90 nanoparticles prepared by wet chemistry with thermal annealing.
abstract: Nanoparticles of Co10Cu90 alloy have been prepared by sonochemical wet method. According to transmission electron microscopy, bimetallic particles with typical diameter of 50-100 nm consisting of nanocrystallites with average diameter of 15-20 nm were obtained. The samples were annealed at 300 degrees C and 450 degrees C. Zero field cooled and field cooled temperature dependences of magnetization in the temperature range of 5-400 K at 50 Oe, as well as magnetization hysteresis loops at 15, 100 and 305 K were measured by vibrating sample magnetometry. Presence of antiferromagnetic phase, most probably of the oxide Co3O4, was observed in as-prepared sample. The lowest coercivity was found for the CoCu sample annealed at-300 degrees C, whereas for as prepared sample and the one annealed at 450 degrees C it was significantly higher. The samples were additionally probed by continuous wave ferromagnetic resonance at room, temperature using a standard X-band electron spin resonance spectrometer. A good correspondence between evolution of the coercivity and the microwave resonance fields with annealing temperature was observed.
authors.affiliation: CIDETEC-Centro de Tecnologías Electroquímicas, Parque Tecnológico de San Sebastián, Paseo Miramón, 196, 20009 Donostia-San Sebastián, Spain.
authors.forename: I
authors.initials: I
authors.lastname: García
authors.forename: J
authors.initials: J
authors.lastname: Echeberria
authors.forename: G N
authors.initials: GN
authors.lastname: Kakazei
authors.forename: V O
authors.initials: VO
authors.lastname: Golub
authors.forename: O Y
authors.initials: OY
authors.lastname: Saliuk
authors.forename: M
authors.initials: M
authors.lastname: Ilyn
authors.forename: K Y
authors.initials: KY
authors.lastname: Guslienko
authors.forename: J M
authors.initials: JM
authors.lastname: González