AI 中文总结
研究探讨氧化物陶瓷快速烧结中原子层面机制，用第一性原理计算，揭示YSZ中缺陷电荷补偿使费米能级上移加速阳离子迁移，如Zr空位电荷转变降低扩散势垒，该机制可推广，对FS技术理论有重要意义。
AI 中文摘要
尽管快速烧结（FS）在材料加工中具有高效性和通用性，但其原子层面的理解仍具有推测性。通过第一性原理计算，我们证明了在典型的Y稳定立方ZrO₂（YSZ）中，一系列缺陷的电荷补偿如何在FS过程中将费米能级E$_F$上移，从而加速阳离子迁移以实现快速质量传输。Zr空位V$_{Zr}^q$的电荷转变使V$_{Zr}^{-4}$在快速烧结过程中的体扩散势垒相对于快速烧结前的V$_{Zr}^0$降低了2eV，这是由非化学计量缺陷的电荷平衡引发的。在Y$_{Zr}$V$_O$Y$_{Zr}$缺陷复合体中，通过消除O空位V$_O$释放的取代缺陷Y$_{Zr}$，在快速烧结前充当电子受体并有利于V$_{Zr}^0$，而过量的V$_O$作为在快速烧结开始时热生成的电子供体，使E$_F$上移并因此支持V$_{Zr}^{-4}$。所提出的YSZ费米能级介导的阳离子扩散机制被推广到其他快速烧结陶瓷，对氧化物陶瓷FS技术的一般理论具有重要意义。
英文摘要
The atomistic understanding of flash sintering (FS) remains speculative, despite its efficiency and versatility in materials processing. Employing first-principles calculations we demonstrate how charge compensation of a range of defects in the prototypical Y-stabilized cubic ZrO$_2$ (YSZ) shifts Fermi level E$_F$ up during FS, thereby accelerating cation migration for fast mass transport. The charge transition of Zr vacancy, V$_{Zr}^q$, reduces its bulk diffusion barrier in V$_{Zr}^{-4}$ during flash by 2 eV, relative to V$_{Zr}^0$ before flash, which is triggered by the charge equilibrium of nonstoichiometric defects. The substituent defect Y$_{Zr}$, released by annihilating O vacancy, V$_O$, in Y$_{Zr}$V$_O$Y$_{Zr}$ defect complex, acts as electron acceptor and favors V$_{Zr}^0$ before flash whereas excess V$_O$, as electron donor thermally generated at the FS onset, upshift E$_F$ and thus support V$_{Zr}^{-4}$. The proposed mechanism of Fermi-level mediated cation diffusion for YSZ is generalized to other flash-sintered ceramics and has considerable bearing on the general theory of FS techniques in oxide ceramics.
