Method for the preparation of aligned fibre samples for magnetic measurement using VSM

Ceramic vibrating sample magnenometer (VSM) samples are usually in the form of a sintered monolith, a sintered pressed pellet, or a powder set in a resin or wax. The problem of mounting an aligned fibre sample, so that it retains alignment whilst remaining fixed in place as it is vibrated in a large magnetic field, was addressed for the first time. The most successful sample preparation method involved the formation of a flat, square composite sample through impregnation of the fibre with a fast-setting resin. Such aligned fibre samples had a fibre volume fraction of 3-4%, but random fibre samples were also prepared, forming a much denser composite with typically 10 times as much fibre in the sample. The magnetic properties of a range of polycrystalline hexagonal ferrite fibres prepared by this method, and the effects of fibre alignment upon those properties, are currently being published in a series of articles.