Abstract
We observed a significant increase of the giant magnetoresistance (GMR) effect (up to 32% after the adequate annealing) and Kondo-like behavior in Cu90Co10 glass-coated microwires. Observed enhancement of the GMR effect can be interpreted considering the formation of the fine Co grains inside the Cu matrix as well as appearance of lamellar nanostructures allowing enhancement of the MR effect after annealing. Observed experimental data are discussed considering the regions with higher Co-ions content responsible for the presence of Co inhomogeneities or clusters and the regions with lower Co-ions content behaving as the magnetic impurities in the metallic host. Observed resistivity minimum on temperature dependence can be described considering Kondo effect mechanism involving magnetic impurities in metals. But the other mechanisms responsible for the resistivity minimum have been considered.
Highlights
A substantial economic difference between multilayered thin films and granular materials is the preparation cost: multilayered materials must be fabricated with multisource MBE and sputtering
Granular materials can be fabricated with much simpler technology.[3,4,8,9,10,11]
Quite recently we reported on considerable improvement of the giant magnetoresistance (GMR) effect after annealing of Cu-Co microwires and on observation of Kondo-like behavior in Cu95Co5 microwires.[17,18]
Summary
Rapid quenching from the melt is quite fast and an effective method for preparation of novel metastable materials with crystalline, amorphous, nanocrystalline or granular structures with a new combination of physical properties (mechanical, magnetic, electrochemical. . .).[1,2,3,4] Most attention has been paid to studies of amorphous soft magnets presenting excellent magnetic softness.[3,4] This magnetic softness is originated from the absence of magnetocrystalline anisotropy in amorphous alloys.[3,4]. Conventional route for optimization of the GMR effect in granular inhomogeneous materials involves appropriate recrystallization of the prepared metastable alloys through the annealing allowing formation of a structure consisting of magnetic nano-sized precipitations into conductive metallic matrix.[9,10] Formation of such structure is related to the phase diagram of the immiscible elements. During last few years studies of glass-coated magnetic microwires prepared using TaylorUlitovsky technique involving rapid quenching from the melt gained considerable attention.[4,11] This inexpensive and fast preparation process method allows preparation of long uniform microwires (up to 10km) with few grams of the master alloy.[4] The diameter of metallic nucleus typically ranges from 1 up to 70 μm, preparation of nanowires using almost the same technique is reported.[12]. In this paper, we present our last experimental results on the influence of annealing conditions on magnetic, transport and structural properties of Cu90Co10 glass-coated microwires
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
