One-step solution fabrication of magnetic chains consisting of jingle-bell-shaped cobalt mesospheres

Abstract

Using a one-step solution phase approach, the authors have synthesized uniform jingle bell-shaped cobalt mesopheres (550–750nm) and assembled the mesospheres into long magnetic chains (20–30μm). All of the cobalt spheres are hollow with ∼40nm thick shells but each contains an ∼200nm diameter solid ball. The nano- to mesoscale structures were realized via reaction of CoCl2∙6H2O and N2H4∙H2O in the presence of polyvinylpyrrolidone (PVP) in an ethylene glycol solution. Magnetic measurements show a coercivity of about 75Oe with a remnance of 9.6emu∕g at 300K. We propose a possible mechanism for the formation of the nanoto mesoscale structures.