Growth mechanism of phases by interdiffusion and atomic mechanism of diffusion in the molybdenum–silicon system

Tracer diffusion coefficients are calculated in different phases in the Mo–Si system from diffusion couple experiments using the data available on thermodynamic parameters. Following, possible atomic diffusion mechanism of the species is discussed based on the crystal structure. Unusual diffusion behaviour is found in the Mo5Si3 and Mo3Si phases, which indicate the nature of defects present on different sublattices. Further the growth mechanism of the phases is discussed and morphological evolution during interdiffusion is explained.

Graphical abstractTracer diffusion coefficients are calculated in different phases in the Mo–Si system from diffusion couple experiments using the data available on thermodynamic parameters. Following, possible atomic diffusion mechanism of the species is discussed based on the crystal structure. Unusual diffusion behaviour is found in the Mo5Si3 and Mo3Si phases, which indicate the nature of defects present on different sublattices. Further the growth mechanism of the phases is discussed and morphological evolution during interdiffusion is explained.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Interdiffusion study in the Mo–Si system conducted. ► Atomic mechanism of diffusion is discussed. ► Unusual diffusion behaviour in the Mo5Si3 and MoSi3 phases is found. ► Low concentration of vacancies and antisites on Mo sublattice is indicated. ► Growth mechanism of phases is discussed.