Aligned hexagonal ferrite fibres of Co2W, BaCo2Fe16O27 produced from an aqueous sol-gel process

Gel fibres of Co2W, BaCo2Fe16O27, were blow spun from an aqueous inorganic sol and collected as an aligned tow blanket with an alignment of over 90%. Upon calcination up to 1300 degrees C, the ceramic fibres were shown by X-ray diffraction to form single-phase crystalline Co2W at 1200 degrees C, an unusually low temperature for this compound to form as the major phase. The formation of Co2W was also accompanied by sudden grain growth, forming crystallites over 10 mu m in length. While this reduced the mechanical strength of the fibres, they were still suitable for use in a composite material.