Characterisation of Mn<inf>0.63</inf>Zn<inf>0.37</inf>Fe<inf>2</inf>o<inf>4</inf> powders after intensive milling and subsequent thermal treatment

Abstract

Commercial Mn-Zn powder (Mn0.63Zn0.37Fe2O4, 93 wt. % and Fe2O3 7 wt. %) was milled 0.5, 1, 2 and 4 hours in a planetary ball mill. The goal was to observe intensive milling influences on oxidation and reduction processes that will happen during subsequent heating. Powders were characterized with XRD, SEM and particle seizer. Subsequent heating was monitored on TGA/DTA in an air atmosphere. After compaction of the milled powders, sintering was also performed in a dilatometric device. Sintered specimens were characterized micro structurally with SEM on a fresh breakage. Obtained differential TGA diagrams suggest intensive changes during prolonged milling of the oxidation kinetics on heating. Ferrite powders changed with milling as well as with second run heating were characterized to enable determination of the potentially best ratio of milling and heating to be applied to obtain the desired microstructure.