Formation of pyrophosphates across grain boundaries induces the formation of mismatched but oriented interfaces in silver phosphate polypods.

Diverse polypods of silver phosphate form via mismatched but oriented interfaces, which are induced by formation of pyrophosphates and stabilized by rotation of phosphates and deformation of Ag-O bonds. [Display omitted] • Diverse Ag 3 PO 4 polypods form via mismatched but oriented interfaces. • Formation of pyrophosphates induces the formation of mismatched but oriented interfaces. • Rotation of phosphates across the interface compensates for the lattice mismatch at the interfaces. • Deformation of Ag-O bonds compensates for the lattice mismatch at the interface. Interfaces and their misfit defects determine the material properties of a wide range of applications, such as electronic devices, photocatalysts, and structural materials. However, current atomic-level understanding of interfacial structures is limited. Here we reveal that a special interfacial structure, a mismatched but oriented interface formed by two differently structured facets, gives rise to Ag 3 PO 4 polypods at room temperature in aqueous solution. Transmission and scanning electron microscopy results suggest that interfaces of {1 0 0} and {1 1 0}({1 0 0}/(1 1 0}), {1 0 0}/{1 1 1}, {1 1 0}/{1 1 1}, and {1 0 0}/{1 0 0} have certain orientation relationships, corresponding to the structural energy minima and coincident site lattices of interfacial atoms, as demonstrated by molecular dynamics simulations. Density functional theory calculations indicate that the formation of pyrophosphates and/or phosphates rotation across the interface, as well as deformation of Ag-O bonds, compensate for the lattice mismatch at the interfaces. Our work opens a new avenue for a much wider range of interfacial structures, allow for a higher diversity of structures, and shines light on tailoring crystal structures, morphologies, and their resulting properties. [ABSTRACT FROM AUTHOR]