The random M hexa-ferrite fibres had Ms values
slightly below single crystal values, as seen in most
polycrystalline samples, high coercivities implying
a small grain size, and were isotropic, shown by
their Mr/Ms values. Therefore any variation in
observed magnetic properties with change in
orientation of the fibre must be due to fibre
alignment effects, and not from alignment of
domains within the fibres. It was also demonstrated
with nickel calibration samples that shape
demagnetisation effects for the square-shaped
samples were negligible.