My first attempt would be carbon tape of the type used in electron microscopy. Other than that, you might try to get one to sit still enough on a roughened glass slide. There should be enough confinement in the rough part of a glass slide to hold one still. I can tell you from experience that the rough glass slide won't hold micron-sized silicate particles still in the EM... too much charging and the particle flys off to find something to dump it's extra electrons onto.
roughened glass? Wouldn't that diffract my focussed input beam? I'm thinking of either 'optically trapping' it, or just placing it in a drop of water on a microscope slide. Also, does anyone know by anychance why they use water in specific?