Mechanochemical decomposition of higher manganese silicides in the ball milling process

Higher manganese Silicides (HMS) were found to decompose into MnSi phase in the ball milling process. Effects of the ball milling parameters on the phase decomposition and on the mean grain size of powders were studied. The decomposition was understood as a mechanochemical effect induced by the high-energy mechanical colliding during ball milling, where the structural features of HMS were supposed to play an important role for the decomposition. The ball milling behaviours of HMS were interpreted in terms of their relationships with the grain size ranges. Grain size effects on the structural stability and the corresponding mechanochemical decomposition were also discussed. Meanwhile, HMS powders down to a few tens of nanometers without noticeable MnSi by-product were achieved by optimizing the ball milling parameters, which supported the idea of functional designs using low-dimensional HMS materials.