Iron oxide shell as the oxidation-resistant layer in SmCo5 @ Fe2O3 core-shell magnetic nanoparticles.
This paper presents a synthesis of magnetic nanoparticles of samarium cobalt alloys and the use of iron oxide as a coating layer to prevent the rapid oxidation of as-made Sm-Co nanoparticles. The colloidal nanoparticles of Sm-Co alloys were made in octyl ether using samarium acetylacetonate and dicobalt octacarbonyl as precursors in a mixture of 1,2-hexadecanediol, oleic acid, and trioctylphosphine oxide (TOPO). Such Sm-Co nanoparticle could be readily oxidized by air and formed a CoO antiferromagnetic layer. Exchange biasing was observed for the surface oxidized nanoparticles. In situ thermal decomposition of iron pentacarbonyl was used to create iron oxide shells on the Sm-Co nanoparticles. The iron oxide shell could prevent Sm-Co nanoparticles from rapid oxidation upon the exposure to air at ambient conditions.
Teng
Xiaowei
X
Department of Chemical Engineering, University of Rochester, Gavett Hall 206, Rochester, NY 14627, USA.
Yang
Hong
H
D003035:Cobalt / Q000737:chemistry*; D005290:Ferric Compounds / Q000737:chemistry*; D006358:Hot Temperature; D007501:Iron / Q000737:chemistry; D008280:Magnetics; D046529:Microscopy, Electron, Transmission; D008956:Models, Chemical; D053758:Nanoparticles / Q000737:chemistry; D036103:Nanotechnology / Q000379:methods*; D010100:Oxygen / Q000737:chemistry; D012493:Samarium / Q000737:chemistry*; D013696:Temperature; D014961:X-Ray Diffraction
D005290:Ferric Compounds; C000499:ferric oxide; D003035:Cobalt; D012493:Samarium; D007501:Iron; C053755:samarium cobalt; D010100:Oxygen