Here we report on the magnetic properties of iron carbide nanoparticles embedded in a carbon matrix. The granular distribution of nanoparticles in an inert matrix, of potential use in various application, were prepared by pyrolysis of organic precursors using thermal assisted chemical vapour deposition method. By varying the precursor concentration and preparation temperature, compositions with varying iron concentration and nanoparticle sizes were made. Powder X-ray diffraction, Transmission Electron Microscopy and Mössbauer spectroscopy studies revealed, the nanocrystalline iron carbide (Fe 3 C) presence in the partially-graphitized matrix. The dependence of magnetic properties on the particle size and temperature (10 K

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The electrical conductivity of nanoporous gold was measured in situ during the charging and decharging of the surface of the metal. The nanoporous gold samples were prepared by the process of selective dealloying of Ag from Au–Ag alloy. Charge was induced on the surface by making the sample a working electrode in an electrochemical cell. The conductivity was observed to vary reversibly with the induced surface charge.

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Mechanical alloying with a Spex 8000 mixer/mill was used to prepare several alloys of the Fe-6 composition, where the solutes X were from groups IIB, BIB, IVB, and VI3 of the periodic table. Using x-ray diffractometry and Mijssbauer spectrometry, we determined the steady-state phases after milling for long times. The tendencies of the alloys to form the bee phase after milling are predicted well with the modified usage of a Darken-Gurry plot of electronegativity versus metallic radius. Thermal stabilities of some of these phases were studied. In the cases of Fe,Ge and Fe$n, there was the formation of transient DO3 and B2 order during annealing, although this ordered structure was replaced by equilibrium phases upon further annealing.