The formation of Fe-Cu composite based on bimetallic nanoparticles

In this paper we suggest a new method of producing a Fe-28 wt% Cu composite by compacting and subsequent sintering of bimetallic nanoparticles made of metals with limited mutual miscibility: iron and copper. The influence of the temperature of annealing on the structure and phase composition of consolidated composite samples has been analyzed. It has been shown that annealing in the temperature range of 200–400 °C induces the processes of low-temperature sintering of copper and iron. These processes are accompanied by the growth of the size of coherent scattering regions and the separation of the metallic components of nanoparticles. During thermal treatment in the range between 400 and 600 °C, adjacent sidewalls of large particles are welded together and large pores emerge in the sample. Further temperature increases cause the sample to shrink and the pores to become smaller. The consolidation of bimetallic nanoparticles consisting of iron and copper and their subsequent sintering allows for obtaining volumetric composites that have homogeneous structure without distinct macroscopic separation of phases as well as high strength characteristics.Russian Science Foundatio

Solution-processed nanostructured ZnO/CuO composite films and improvement its physical properties by lustrous transition metal silver doping

This paper has reported the fabrication and characterization of pristine, and silver (Ag)-doped nanostructured ZnO/CuO composite thin films that have not been previously reported. The thin films were synthesized by the successive ionic layer adsorption and reaction (SILAR) technique. The morphological, crystalline structure, optical and electrical characterizations of the films have been achieved utilizing scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS), atomic force microscopy (AFM), X-ray diffraction (XRD) analysis, Fourier transform infrared spectrum (FTIR) analysis, ultraviolet-visible (UV-Vis) spectrophotometry and the four-point probe measurements. Particle sizes of pristine and Ag-doped ZnO/CuO thin films were found to vary from 32 to 58 nm. Crystallite size was changed from 16.40 to 18.90 nm with changing Ag dopant in the ZnO/CuO composite film. FTIR spectra that have the absorption peaks at similar to 725 and similar to 510 cm(-1) referred to the stretching vibration of Zn-O and Cu-O bonds during the synthesis of ZnO/CuO nanofilms. The bandgap values of ZnO/CuO composite films increased from 2.05 to 2.36 eV as Ag content increased from 0 to 2 M%. The activation energies of the samples were obtained from the Arrhenius plots of sigma versus 1/T. The multiple activation process was observed. It was noteworthy that Ag-doping results in a significant difference in conductivity at all temperature values