Negative-ion implanter for powders and its application to nanometer-sized metal particle formation in the surface of glass beads

Abstract

We have developed a negative-ion implanter for uniform implantation into each powder surface without particle scattering. It consists of a plasma sputter-type negative-ion source, a mass separator, an acceleration tube, a lens, X–Y deflectors, a 90° deflector, and a Faraday cup with an agitator. The electrostatic 90° deflector bends a horizontal beam to a vertical direction and leads it into the Faraday cup. The agitator is an electromagnetic vibrator at a frequency of 120 Hz, which mixes particles for whole surface treatment and uniform implantation. In this implanter, we obtained no scattering implantation for spherical oxide beads with diameters ranging from 5 to 1000 μm in an agitated state, and also obtained a good uniformity of implanted atoms among beads. For an application of the negative ion implantation into powders, copper ions were implanted into soda-lime glass beads and plates at conditions of 50 and 30 keV, respectively, with 1×1017 ions/cm2. In linear optical properties, both implanted samples show a clear absorption at a photon energy of 2.2 eV due to resonance absorption of copper surface plasmon. In addition, the implanted glass plate shows the large third-order nonlinear susceptibility, χ(3)=1.3×10−7 esu. These results suggest the existence of copper nanometer-sized particles in glass.