Synthesis, crystal structure, and properties of novel perovskite oxychalcogenides, Ca2CuFeO3Ch (Ch = S, Se)

TL;DR

This study reports the synthesis and structural characterization of two new calcium-based layered perovskite oxychalcogenides, Ca2CuFeO3S and Ca2CuFeO3Se, which are the first of their kind involving calcium and exhibit semiconducting properties.

Contribution

First synthesis and structural analysis of calcium-based layered perovskite oxychalcogenides Ca2CuFeO3S and Ca2CuFeO3Se, expanding the family of oxychalcogenides with potential for electronic applications.

Findings

Crystallize in P4/nmm space group with specific lattice parameters.

Exhibit semiconducting behavior with decreasing energy gap from sulfide to selenide.

First layered chalcogenide perovskites involving calcium.

Abstract

Two new perovskite oxychalcogenides, Ca2CuFeO3S and Ca2CuFeO3Se, have been synthesized in evacuated quartz tubes. They crystallize in P4/nmm space group with lattice parameters a = 3.8271(1), c = 14.9485(2) {\AA} and a = 3.8605(1), c = 15.3030(2) {\AA} for Ca2CuFeO3S and Ca2CuFeO3Se, respectively. They appear to be the first layered chalcogenide perovskites involving calcium and are structural analogs of the corresponding Sr and Ba compounds. The new compounds exhibit semiconducting properties with energy gap decreasing from the oxysulfide to the oxyselenide. Possibility of introducing Ca2+ into structures of known layered oxychalcogenides and oxypnictides is discussed.