Manganese-magnesium-zinc ferrite - by dissolving ferric manganese,magnesium,and zinc cpds in aq hydroxy acid soln,evapg and

摘要

ferrite magnetic cores for magnetic memories is produced by (a) dissolving cpds of trivalent Mn, Mg, and Zn in an aqs. soln of a hydroxy acids of for (I), or an alpha, beta-unsatd acid formed by splitting a molecule of water from the hydroxy acid, (b) evapg. the soln to dryness, (c) heating the dry residue to form a ferrite, (d) cooling the pdt. (e) mixing the pdt. with a binder, (f) converting the mixt. into an annular body, of (g) sintering the body of heating at a temp. 1000 degrees C. The amts of metal cpds in stage(a) are chosen to give a sintered annula annular body of formula (II), and the dimensions of the annular body are chosen so that the sintered annular body has an outer dia. of 0.9mm, and an inner dia. which is more than half the outer dia. MnaMgbZncFedOe (where R1 and Ri are each H, CH2COOH or CHOHCOOH; 0.4 a 1.1; 0.1 b0.65, Oc0.3; 1.65 (d2.0; a+b+cad=3 and 3.9 e 4.1.