CuSe-based layered compoundBi2YO4Cu2Se2as a quasi-two-dimensional metal

Abstract

We have investigated the physical properties of a new layered oxyselenide ${\mathrm{Bi}}_{2}{\mathrm{YO}}_{4}{\mathrm{Cu}}_{2}{\mathrm{Se}}_{2}$, which crystallizes in an unusual intergrowth structure with ${\mathrm{Cu}}_{2}{\mathrm{Se}}_{2}$ and ${\mathrm{Bi}}_{2}{\mathrm{YO}}_{4}$ layers. Electric transport measurement indicates that ${\mathrm{Bi}}_{2}{\mathrm{YO}}_{4}{\mathrm{Cu}}_{2}{\mathrm{Se}}_{2}$ behaves metallic. Thermal transport and Hall measurements show that the type of the carriers is holelike and it may be a potential thermoelectric material at high temperatures. First-principles calculations are in agreement with experimental results and show that ${\mathrm{Bi}}_{2}{\mathrm{YO}}_{4}{\mathrm{Cu}}_{2}{\mathrm{Se}}_{2}$ is a quasi-two-dimensional metal. Further theoretical investigation suggests the ground states of the ${\mathrm{Bi}}_{2}{\mathrm{YO}}_{4}{\mathrm{Cu}}_{2}{\mathrm{Se}}_{2}$ type can be tuned by designing the blocking layers, which will enrich the physical properties of these compounds.