Perpendicular orientation of magnetic powder

Behavior of perpendicular orientation of the acicular ( ratio 7/1 ) and ultra fine (
\ell =0.2\sim0.3 \mu
m) particles in the thin coating type media was investigated by magnetic measurements. The perpendicular anisotropy coatings which contain the acicular γ-Fe
2
O
3
particles or Co-γ-Fe
2
O
3
particles can be obtained by a continuous process line. The degree of perpendicular orientation of the moments or the particles in the tapes are discussed by the measurements of Mössbauer spectra.