2015 Volume 56 Issue 3 Pages 292-296
Temperature (T)-dependence of electrical resistivity (ρ) and magnetization curves have been observed for Fe and Si nano-particle (NP) composite assemblies prepared using a double-source-plasma-gas-condensation cluster deposition system. With increasing T, ρ monotonically decreases for the Fe composition, cFe < 0.6, where the Si NP networks are predominant (a semiconductor type conduction), while it monotonically increases for cFe > 0.6, where the Fe NP networks are formed (a metallic conduction). With increasing cFe, saturation magnetization monotonically increases, while magnetic coercivity increases for cFe < 0.4 and gradually decreases for cFe > 0.6. In these Fe and Si NP composite assemblies, magnetic dipole interactions between Fe NPs are reinforced by reductions in inter-particle distances though they are averaged by random configurations of Fe and Si NPs, and random orientations of magnetic moments of Fe NPs. Magnetic exchange interactions are also induced but not much enhanced with cFe due to loose contacts between Fe NPs.
