Effect of ball milling on the sintering performance of indium-gallium-zinc oxide ceramics: The diffusion mechanism and lattice distortion of milled powders

Abstract

The mechanisms inducing lattice distortion and grain boundary diffusion in mixed In2O3–Ga2O3-ZnO (IGZO) powders were investigated during ball-milling treatment at different rotation speeds. After sintering, the highest relative densities for the sintered IGZO compacts were 92.87%, 98.72%, and 99.12% at rotation speeds of 100 rpm, 200 rpm, and 300 rpm, respectively, and the corresponding grain growth activation energies were 78.78, 67.17, and 49.52 kJ/mol. The sintering process of InGaZnO4 ceramics was shown to be dominated by grain boundary diffusion. X-ray diffraction line profile analysis indicated that the highest average lattice distortion of IGZO powders milled at 200 rpm and 300 rpm was 2.85 and 10.27 times higher, respectively, than that of IGZO powder milled at 100 rpm. The enhancements of the sintering properties of the IGZO powders induced by the faster milling speeds were attributed to the higher lattice distortion energies and shorter diffusion distances of the elements. This elucidated the mechanism behind the high-energy ball-milling process for achieving enhanced sintering performances in ceramic powders.