Synthesis of nanosized metal platelets

The synthesis of nanosized powders with targeted properties and the assembly of the powders is of considerable importance to the microelectronics industry because of the pervasive drive to miniaturize components. In the current work, synthesis of nanosized silver (Ag), nickel (Ni) and silver/palladium (Ag/Pd) metal platelets was studied. The platelets were synthesized in the lamellar bilayer phase region (neat phase D) of the octylamine-water binary system. Previously the synthesis of tabular particles between the lamellar bilayers has not been studied. In the self-assembly system amylamine was used as co-surfactant to increase the phase stability of the lamellar region. The influence of the synthesis conditions and the concentrations of the system components on morphology and size of the platelets were examined. Low angle x-ray diffraction studies revealed that the water/surfactant molar ratio (R) has a strong influence on the thickness of bilayers (d₁+d ₂) and consequently particles grown in them. Atomic force microscopy (AFM), scanning electron microscopy (SEM) and high-resolution transmission electron microscopy (HRTEM) studies have shown the effect of R on platelet thickness (t) and face diameter (a). Thickness and face diameter of platelets is controlled by regulating the bilayer dimensions by changing R. Ag, and Ni platelets with face diameters ranging from 12 nm to 83 nm, and 50 nm to 160 nm, and thicknesses from 0.3 nm to 5 nm, and 0.6 nm–8 nm respectively, have been synthesized at room temperature. In Ag/Pd experiments, a single composition point was studied. Ag/Pd platelets with face diameters and thicknesses around 150 nm and 2 nm respectively were synthesized.; In nanosized silver (Ag) metal platelets, thickness values for a selected sample were also obtained by a novel TEM holography technique and compared to those measured with AFM.; Electrophoretic deposition (EPD) technique was applied as a thick/thin film forming method for electrodes. Silver and silver/palladium particles were laid down by EPD method. Green thickness of silver electrodes produced was about 220 nm to 1.3 μm with less surface roughness (RMS surface roughness ∼ 37 nm). Silver/palladium particles were also deposited down to 16 nm green thickness with less surface roughness (RMS surface roughness ∼ 0.7 nm).