Ultra-dense dislocations stabilized in high entropy oxide ceramics.

ABSTRACT: Dislocations are commonly present and important in metals but their effects have not been fully recognized in oxide ceramics. The large strain energy raised by the rigid ionic/covalent bonding in oxide ceramics leads to dislocations with low density (∼10⁶ mm^-2), thermodynamic instability and spatial inhomogeneity. In this paper, we report ultrahigh density (∼10⁹ mm^-2) of edge dislocations that are uniformly distributed in oxide ceramics with large compositional complexity. We demonstrate the dislocations are progressively and thermodynamically stabilized with increasing complexity of the composition, in which the entropy gain can compensate the strain energy of dislocations. We also find cracks are deflected and bridged with ∼70% enhan

SUBMITTER: Han Y 

PROVIDER: S-EPMC9130511 | biostudies-literature | 2022 May

REPOSITORIES: biostudies-literature