Interface structure dependent step free energy and grain growth behavior of core/shell grains in (Y, Mg)-doped BaTiO3 containing a liquid phase

Enhanced compressive strength of porous alumina realized by synergy between La‐doping and two‐step sintering

“…This is due to the reduced grain growth driving force (Equation ()) as appreciable grain growth occurs at T 1 . This can be understood by reconsidering our previous results, 30–32 where we suppressed AGG when Δ g c decreased as the average grain size increased. As a result, we were able to avoid AGG behavior from T 1 and T 2 based on the understanding of grain growth behavior.…”

“…This can be understood by considering the relationship Δ g max < Δ g c , where Δ g max increases as sintering progresses and some grains grow to AG when Δ g c is exceeded. There have been several reports of SGG converting to AGG 29,30 . However, at 1600°C, it appears that Δ g max < Δ g c , with Δ g c reduced by the temperature.…”

“…There have been several reports of SGG converting to AGG. 29,30 However, at 1600 • C, it appears that Δg max < Δg c , with Δg c reduced by the temperature. Therefore, from the beginning of sintering, a number of grains have already grown into AG.…”

“…The main point of the theory is grain structure dependence of the grain growth behavior, which is characterized by AGG when the grain shape is faceted and by normal grain growth (NGG) when the grain shape is rough. This grain structure dependence stems from the coupling effect between the growth driving force (Δ g ) and the critical driving force (Δ g c ) of each grain, which results in different velocity‐determining steps that control the movement velocity ( v ) of each grain 28–30 . Δ g is expressed by Equation () and is determined by the average grain size and the size relationship of each individual grain, giving it a range in a single polycrystalline system.…”

“…This grain structure dependence stems from the coupling effect between the growth driving force (Δg) and the critical driving force (Δg c ) of each grain, which results in different velocity-determining steps that control the movement velocity (v) of each grain. [28][29][30] Δg is expressed by Equation (1) and is determined by the average grain size and the size relationship of each individual grain, giving it a range in a single polycrystalline system. This means that the largest grain has the largest maximum driving force (Δg max ).…”