Papers by Keyword: Ag-Cu

Abstract: For revealing internal atomic processes in bimetallic nanoparticles, individual hemispherical Ag-Cu alloy particles were grown by direct current (DC) magnetron sputtering. Phase separation of particles was found to be size- and composition-dependent. Particles smaller than 5 nm in diameter remained as a solid solution of the components for all tested compositions (15-80 at.% Ag). At 15 and 30 at.% Ag compositions phase separation was observed only for particles above 5 nm in diameter. Computer simulations by Stochastic Kinetic Mean Field model reproduced the size-dependence of the decomposition and the internal structure of two-phase particles. Theoretical explanation is given for the composition dependence of the phase separation tendency.

Abstract: Polymers are excellent host materials for nanoparticles of metals and semiconductors. PVAAgCu nanocomposite was synthesized from chemical reduction, whereas PANIAgCu nanocomposite was synthesized by chemical oxidative polymerization. PVAAgCu and PANIAgCu thin films were deposited on the glass substrate by spin coating technique. The films were characterized by using XRD and AFM. The sensitivity of the samples was analyzed by IV measurement. The peaks in XRD patterns confirm the presence of Ag-Cu nanoparticles in face centered cubic structure. AFM images show the roughness of PVAAgCu and PANIAgCu increased as Ag concentration decreased and Cu concentration increased. I-V measurements indicate that the change in the current of the films increases with the presence of E. coli. The sensitivity on E. coli increases for PVAAgCu and PANIAgCu thin films with high concentration of Cu.

Abstract: This research focuses on Ag-Cu powder particles processing by mechanical alloying (MA) route. The powder mixture is representative for the eutectic composition, respectively 72%wt. Ag + 28% wt. Cu. The milling process is developed in high energy ball mill Pulverisette 6, using different size for the milling balls, in wet conditions for 80 hours. One of the most important parameter studied in this research is the particle size distribution of the processed powder mixture. Thus, it changes along the milling time, from 10…75 µm at the beginning of MA process up to (60 – 80) nm at 80 h. The milling parameters will be optimized in future research depending on the particle size distribution related with thermophysical and thermodynamic properties focused on electrical and optical properties improvement.