Magnetic and storage properties of co-modified pigments

Co-modified iron-oxide is widely used for high-density magnetic recording. The modification with Co is necessary to yield an increase of coercivity, which causes a higher reproduce voltage at short wavelengths. The positive improvement of the coercivity is until now usually accompanied by a loss of magnetic and aging stability. In this paper we show that a newly developed Co-modified ferrite material overcomes the shortcomings of the previous types of Co-containing pigments. The improvements include an excellent temperature and aging stability as well as a superior general storage performance in comparison to former Co-modified iron-oxides.