Preparation of Exfoliated Graphite Containing Ferromagnetic Iron, Cobalt, and Nickel Alloys

Abstract

A new technique has been proposed for the synthesis of metal-containing exfoliated graphite: by expanding a mixture of expandable graphite with metal (Fe³⁺, Co²⁺, and Ni²⁺) nitrates and a reducing agent (melamine). Heat treatment of such a mixture in an inert (nitrogen) atmosphere at 900°C leads to the formation of exfoliated graphite, with fine metallic alloy (FeCo, FeNi, FeCoNi, or CoNi) particles located on its surface. The exfoliated graphite samples thus prepared have low loose bulk density (down to 6 g/L) and high saturation magnetization (up to 41.2 emu/g).