Low Energy Metal Ion Beam Production with a Modified Freeman-Type Ion Source for Development of Novel Catalysts

Abstract

Interactions of indium (In) and silicon (Si) atoms have been found to catalyze certain organic chemical reactions with high efficiency. In a recent paper [S. Yoshimura, et al., Appl. Surf. Sci., 257, 192 (2010)], it has been demonstrated that an In injected SiO2 thin film formed under specific ion beam conditions catalyzes a reaction of benzhydrol with acetylacetone. In this study a technique to implant bismuth (Bi) ions into SiO2 thin films has been developed with highly controlled ion doses and injection energies for the formation of thin films that promote Bi(III) catalysis in organic chemistry. For this purpose, the Freeman-type ion source of our beam system was modified with a new sputtering target. In addition, sticking probabilities of Bi have been obtained with the use of a quartz crystal microbalance. Although efficiency of catalytic reactions by a Bi implanted SiO2 thin film is yet to be improved, the technique provides a Bi-Si based novel catalyst of a thin film type.

Low Energy Indium or Gallium Ion Implantations to SiO₂Thin Films for Development of Novel Catalysts

“…In Fig. 7(b), the measured sticking probabilities of Ga are compared with those of In [6] and Au [5] by closed circles and closed triangles, respectively. Figure 7(b) also shows that our measurement of sticking probabilities of Au agrees with those obtained by other experimental group [22].…”

“…Especially, catalytic effects induced by interactions between In and silicon (Si) have attracted much attention [1,2]. In earlier papers [4][5][6][7], we have proposed an experimental method in which implantations of metal ions such as In into Si containing materials by ion beam injection is useful for preparing such catalytic materials.…”