Low-temperature topotactic oxidation using the solid-state oxidant Zr-doped CeO2

Superconductivity and improved electrical conduction in anti-ThCr2Si2-type RE 2O2Sb and RE 2O2Bi with pnictogen square net

Layered compounds have shown rich physical properties such as high-temperature superconductivity. Recently, monatomic honeycomb lattice systems, such as graphene, have been studied extensively, whereas monatomic pnictogen square nets in layered compounds also exhibit interesting electronic properties owing to their unusual negative valence states. Among them, anti-ThCr2Si2-type RE 2O2 Pn (RE = rare earth, Pn = Sb, Bi) with monoatomic Pn square nets were recently found to exhibit interesting electronic properties such as superconductivity and high carrier mobility. In this article, we review recent studies on crystal structures, electronic properties, and thin-film growth of RE 2O2 Pn.