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ArF Laser-induced Deposition of Carbon Encapsulated CoFe Nanoparticles

2009; Institute of Physics; Volume: 25; Issue: 8 Linguagem: Inglês

10.1149/1.3207701

2151-2051

Radek Fajgаr, Zdeněk Bastl, Ján Šubrt, Nataliya Murafa, M. Maryško,

Diamond and Carbon-based Materials Research

The decomposition of the gaseous acetylene - Fe(CO)5 - Co(CO)3(NO) mixtures induced by a single ArF laser pulse is a very efficient and novel method for formation of amorphous cobalt/iron alloy nanoparticles completely encapsulated in amorphous carbon shell. The properties of the CoFe(core)-carbon(shell) nanocomposites were examined by spectroscopy, microscopy and diffraction techniques. Magnetic measurements revealed the superparamagnetic behaviour of the as-prepared samples with diameter ≈ 5 nm at temperatures above 200K. The properties of the CoFe alloy nanoparticles annealed at 600, 900 and 1150oC were studied. Heating leads to structural changes in both the alloy core and the carbon shell. The cobalt/iron core crystallizes as syn-wairauite and carbon affords graphite outer part.