Adsorption of cis-but-2-ene on iron oxide films

Abstract

Iron oxide films consisting of small-sized maghemite particles were formed by spin-coating a solution of iron nitrate dissolved in ethylene glycol onto a quartz plate. These maghemite particles, of a homogeneous size level, were in a two-dimensional array over the quartz plate, so that the film thickness was controlled by the particle size. Heats of adsorption of (Z)-but-2-ene on films of various thicknesses were measured for comparison with those on maghemite powders, leading to the conclusion that films thicker than 3300 Ă behave like the powders, but that films thinner than 3300 Å adsorb (Z)-but-2-ene much more strongly than do powders. This is discussed in terms of the variation in saturation magnetization of the films with film thickness.