SYNTHESIS AND CHARACTERIZATION OF NANOSCALE AG-PD ALLOY PARTICLES

Monodisperse colloidal dispersions of bimetallic Ag-Pd (70/30 at. wt.% ) particles have been prepared at 120 degrees C from ethylene glycol s olutions of polyvinyl pyrrolidone (PVP) and silver and palladium nitra tes. Characterization of these particles by X-ray powder diffraction r eveals a bimetallic and crystalline silver-palladium alloy. From the s cattering peak positions on the diffractogram, the lattice parameter o f the face centered unit cell was calculated and subsequently refined. Particle size and shape were assessed from transmission electron micr ographs. The average particle size of these colloids was found to depe nd on the amount of precursor and PVP added. A PVP/precursor weight ra tio of 10.3 yields particles with 14 nm diameter, while a ratio of 47 yields 7 nm particles.