Synthesis and electrical transport properties of Bi2O2Se single crystals

we have reported the synthesis, electrical resistivity ρ(T), Hall coefficient (RH) and magnetoresistance (MR) of Bi2O2Se single crystals with layered tetragonal structure (space group I4/mmm). The lattice parameters obtained after Rietveld refinement are a = b = 3.897 Å, c = 12.237 Å, respectively. ρ(T) and RH measured in the temperature range from 2 K to 300 K show high carrier concentration extrinsic semiconductor behavior. At higher temperatures (130-300 K), the resistivity is dominated by phonon scattering mechanism, as manifested by ρ(T)  ∝  T1.5. The magnetic field dependence of resistivity is positive in the whole temperature range. The MR at 2 K increase monotonically with magnetic field and manifest very weak saturate trend up to 9 T where it reaches its maximum value with Δρxx/ρxx  ≈ 100%.