Characterization of Ba-Ferrite Suspensions

Although the particulate magnetic recording industry is mature, there still remains an unsolved problem of dispersion quality which plagues any coating process involving unstable particle suspensions. We examine this issue in light of three different characterization techniques: rheomagnetic, rheooptic, and rheological measurements. We use these techniques to study the dispersion state of various single domain magnetic particles (rod-like γ-Fe2O3 or CrO2 and plate-like Ba-Ferrite). Theory is also developed to interpret data and provide a unified description of characterization of dispersion quality.