Patents Assigned to BASF Aktiengesellschat
  • Preparation of cobalt-containing isotropic magnetic iron oxides
    Patent number: 4755315
    Abstract: A process for the preparation of cobalt-containing isotropic magnetic iron oxides which are based on gamma-iron(III) oxide, contain from 2 to 7% by weight of cobalt(II) ions and less than 2% by weight of Fe(II) ions, the percentages in each case being based on the iron oxide, and have a particle length of from 0.08 to 0.30 .mu.m, a length/width ratio of from 1.5 to 3.5:1 and a specific remanent magnetization after saturation of not less than 60 nTm.sup.3 /g.
    Type: Grant
    Filed: February 12, 1987
    Date of Patent: July 5, 1988
    Assignee: BASF Aktiengesellschat
    Inventors: Werner Steck, Rainer Feser, Helmut Jakusch, Peter Rudolf, Guenter Vaeth, Udo Kullmann