Effects of Mechanical Processing Conditions on the Synthesis of Oxide Nano-particles

Abstract

Mechanical synthesis of lanthanum manganite powder was investigated using attrition-type milling without any extra heat assistance. The starting materials were lanthanum oxide and manganese oxide powders. The BET equivalent diameters of them were 300 nm and 35 nm, respectively. In this paper, electric load conditions controlled by the rotor speed were changed to make clear their effect on the reaction. At 1 kW loading, lanthanum manganite was not synthesized even by 120 min processing. At 2 kW, the authors already reported that lanthanum manganite was successfully synthesized. However, the synthesized powders were agglomerated to form large granules. At 3 kW, synthesis was remarkably accelerated and well crystallized lanthanum manganite was synthesized. The BET equivalent diameter of the synthesized powder was larger than that processed at 2 kW. However, the synthesized powder didn't form large agglomerates. As a result, it was suggested that critical mechanical conditions exist to initiate the reaction.