|
Abstract
|
Ordered Fe100–x Crx (x=0, 1, 2.5, 4, 5, 6, 7.5, 10, 12) alloy nanowires with average diameter about 37nm have been prepared in pores of homemade an anodic aluminum oxide (AAO) template by applying alternating current (ac) electrodeposition method of sulfate salt of Cr and Fe ions at room temperature. The structure and morphology of nanowire arrays embedded into AAO templates were considered by using scanning electron microscopy (SEM) and X-ray diffraction (XRD). Also, magnetic properties of NWs and composites were investigated by an alternating gradient force magnetometer (AGFM).The alloying effects of Cr on various properties of FeCr nanowire investigates, including crystal structure and magnetic properties, thermal treatment. The results indicate that the Coercivity decreased from 1510 Oe to 1190 Oe with increasing Cr ions concentration in the electrolyte from 0% to 12% while the squareness increased from 0.84 to 0.96. The X- ray diffraction (XRD) spectra of the Fe and Fe92.5Co7.5 nanowires demonstrate, Cr atoms placed in some sites of Fe atoms and no change in crystal structure accrued. Fe and FeCr nanowires were annealed for 20 min at various temperatures (300, 450, 450, 550, 550 and 600 °C) in an Ar atmosphere. The coercivity of Fe100–x Crx (x>2.5) increased more than Fe nanowires by annealing. XRD pattern of as-deposited Fe nanowires demonstrated that the Fe have a bcc structure with strong peaks of (110) and (200). After annealing Fe atoms were oxidized by remained oxygen at AAO structure and peaks of Fe2O3 appeared (at 21.6 o and 28.2 o) in XRD spectra.
|