Influence of porosity and preparation conditions on the properties of gamma -Fe/sub 2/O/sub 3/

A summary is presented of the results of a development program for gamma -Fe/sub 2/O/sub 3/ particle synthesis which lasted two years and whose aim was the preparation of improved products for magnetic recording. The focus of the exercise was the achievement of improved high-frequency recording characteristics. The goal has been achieved in two steps: the first was the realization of the limits of coercivity attainable by decreasing the particles size, while the second was entirely related to the optimization of the total amount and of the type of porosity and porosity distributions. Important conclusions on the correlation between the size of the switching unit (dependent, among other things, on porosity) and the applicative properties can be drawn from the results.<
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