| Flake gold powders were synthesized in an aqueous solution by reducing HAuCl4 with histidine (His), using gum arabic as a protective agent and dimethyl diallyl ammonium chloride (DMDAAC, Dia) as a structure-directing agent. The effects of dosage (molar ratio), temperature, and initial pH on the size and morphology of the gold powders were investigated. The optimal conditions for preparing two-dimensional micron-sized flake gold powders were determined as follows: nHis:nAu=1:1, nDia:nAu =3:2, temperature of 40 °C, and initial pH of the reaction solution is 1.2. The hexagonal and triangular flake gold powders with lateral dimensions of 3~4 μm and thicknesses of 100~300 nm were obtained. When co-fired with domestic LTCC green tape, the flake gold powder exhibited excellent sintering compatibility and low electrical resistance. |
