“…Notably, an abrupt and drastic increase in the standard deviation of the grain‐size distribution of the samples is observed when the value of x reaches 0.1. This suggests that the grain‐size distribution is more discrete, which can have a negative effect on the dielectric properties
41 . The non‐uniformity of grain morphology is mainly attributed to two aspects: different grain sizes caused by uneven nucleation
42 and the production of a certain amount of liquid phase during the sintering process, resulting in the driving force for grain growth dispersed in the liquid phase satisfying the following formula
43 :
where γ sl and V m are the solid–liquid interface energy and the corresponding molar volume fraction, respectively, and r * is the grain size that neither dissolves nor grows.…”