Ferrite Synthesis II

Abstract

The systematic investigation of the MgO-MnO-Fe₂O₃ system for which preliminary results were reported in Memorandum M-2442, has been extended and verified. The patterns of loop squareness vs. composition have remained essential unchanged, but one new region has been added to the interpretation diagram for the loop-squareness patterns. The tentative phase interpretation which was offered in M-2442 has been confirmed by micro-structure studies and has been extended by considering the chemistry of memory-core constituents during heat cycling. A hypothesis is made that any magnetic ferrite phase containing small amounts of Mn₃O₄ in cubic solid solution is potentially square hysteresis-loop material. Magnetic measurement taken on the various compositions include coercive force and magnetic induction at saturation and at maximum loop-squareness conditions as well as flux reversal times at maximum loop-squareness. The magnetic measurement are plotted, using the above compositional hypothesis.