Synthesis and Self-Assembly of Films Containing FeCoPt Nanoparticles

Abstract

ABSTRACTFe49Co7Pt44 and Fe40Co17Pt43nanoparticles were synthesized by simultaneous chemical reduction of platinum acetylacetonate and cobalt acetylacetonate and thermal decomposition of iron pentacarbonyl. As-prepared the particles had a disordered face-centered cubic lattice with an average diameter of 3.2 nm and were superparamagnetic. These particles were well dispersed in a 50/50 mixture of hexane and octane. The particles self-assembled into ordered superlattices when deposited onto carbon coated Cu TEM grids or onto single crystal Si (100) substrates. After vacuum annealing (from 500°C to 700 °C), the particles transformed to the tetragonal phase. The coercivity of the film strongly depended on the composition and annealing temperature. For the Fe49Co7Pt44film, coercivity of 8700 Oe and a squareness of 0.75 after annealing at 700 °C for 30 minutes. XPS shows existance of oxidized iron and cobalt on the surface of film.