Novel supercell compounds of layered Bi–Rh–O with p-type metallic conduction materialized as a thin film form

Layered oxides have been intensively studied due to their high degree of freedom in designing various electromagnetic properties and functionalities. While Bi-based layered supercell (LSC) compounds [BinOn+δ]-[MO2] (M = Mn, Mn/Al, Mn/Fe, or Mn/Ni; n = 2, 3) are a group of prospective candidates, all of the reported compounds are insulators. Here, we report on the synthesis of two novel metallic LSC compounds [BinOn+δ]-[RhO2] (n = 2, 3) by pulsed laser deposition and subsequent annealing. With tuning the thickness of the sublattice from Bi2O2+δ to Bi3O3+δ, a dimensionality-dependent electrical transport is revealed from a conventional metallic transport in n = 2 to a localized transport in n = 3. Our successful growth will be an important step for further exploring novel layered oxide compounds.