Narrow band size selection of ultrafine particles - formed by laser ablation, for deposition or detection

摘要

Narrow band size selection of ultrafine particles, generated from a solid target by a laser beam, is effected by transferring the particles in a carrier gas stream to a region in which unipolar charging of the particles occurs and then transporting the particles through an aperture into the capacitive field of an electric selector and/or the magnetic field of a magnetic selector having parameters selected to cause beam splitting in the interesting particle size range so that a very narrow band particle size distribution is obtd. at a detector or substrate. USE/ADVANTAGE - The process is useful for selection of 1-10nm. dia. particles of free, deposited or matrix-embedded materials for use e.g. as phosphors, nonlinear optical materials, cathodes, miniature information stores, quantum dots, ductile ceramics, ultra-high resolution light sensitive films, metallic particles embedded in oxide (for nano-size electrical conductivity phenomena or percolation effects), magnetic recording materials, and catalysts. It provides reliable selection of ultra-fine particles in a very narrow size distribution.