Theoretical study on the stability and electronic property of Ag2SnO3

Bulk crystal properties of Ag2SnO3 were investigated with the advantage of density functional theory. The whole structure has layered feature: hexagonal metallic planes formed by Ag atoms and distorted octahedrons of SnO6 clusters are configured alternatively along c axis of hexagonal cell. The cohesive energy is about −2.792 eV/atom, which is less than SnO2. The Debye temperature of Ag2SnO3 is about 231.6 K, and the bulk and shear moduli are 62.13 and 20.63 GPa, respectively. Band structure and DOS show the compound has a small pseudo-band gap value of 1.0 eV and so may be a semiconductor. When checking the PDOS intensity at the Fermi surface of Ag atoms, a weak metallic character can be seen. The distortion mechanism becomes less effective to reduce the total orbital energy both in SnO2 and in Ag2SnO3 and as a result the bond lengths of Sn–O are intended to be isotropy.

The structure of Ag2SnO3 studied here has a hexagonal primitive cell with the space group of P6322, Ag atom which located in SnO6 layer, almost coplanar with Sn atoms has a large coordination numbers as 12, including 6 Sn–O bonds and 6 Sn–Ag bonds. Interestingly, the whole structure has layered feature, hexagonal metallic planes formed by Ag atoms and distorted octahedrons of SnO6 clusters are configured alternatively along c axis of hexagonal cell. These characters are similar to magnetoresistive manganites and superconducting cuprates, may be a new structure of superconductivity structure or charge ordering phenomenon for functional materials.Figure optionsDownload as PowerPoint slide