P INVESTIGATION OF A HYSTERESIS LOOP OF COBALT-

S Hysteresis loops of ferromagnetic ferrites1 can be divided into three types: normal, contracted and rectangular. The majority oftferrites have a normal loop.. It is character-ized by the fact that the relation of remanence Br to gaturation B for a given field H is less than or equal to 0.5. A contracted loop is obtained by slow cooling nickel and nickel-zinc ferrites with admixtures of CoO [1]. According to the authors, it corresponds to a microhetrogeneous system comprised of two types of crystals of similar structure with slightly different parameters. In twin ferrites of Ni, Mn, Pb, Cu, Cd, Zn, and Mg containing admixtures of CoO and slowly cooled a contracted loop was observed with measurements in average-strength fields. A certain excess of Fe 203 aids in the appearance of a contracted loop [2]. A rectangular loop has BIBs 2 0.75 and clearly expressed angle