Synthesis, thermal evolution and optical properties of CuZn alloy nanoparticles in SiO2 sequentially implanted with dual ions

CuZn alloy nanoparticles (NPs) embedded in amorphous SiO2 were fabricated by means of sequential implantation of 45 keV Cu and Zn ions at the same fluence of 1 x 10(17) cm(-2) together with subsequent annealing at 500 degrees C in nitrogen ambient. Such binary alloy NPs presented an intense surface plasmon resonance (SPR) absorption peak at about 515 nm. After 600 degrees C annealing, the already formed alloy NPs were found to be decomposed. The Zn atoms separated from the alloy NPs diffused toward the surface of sample, while the Cu atoms nearly stayed at original sites to form Cu NPs, inducing a SPR absorption signal much stronger than that detected in the Cu singly implanted sample after the same annealing. Moreover, a weak photoluminescence band around 558 nm was revealed in the sequentially implanted sample after annealing. The possible luminescent mechanism was discussed. (C) 2012 Elsevier B.V. All rights reserved.