2019 Volume 3 Issue 1 Pages 28-33
An electronic and magnetic phase diagram of a mixed anion layered compound, Sr2CrFeAsO3−δ, is demonstrated. Sr2CrFeAsO3−δ is composed by a carrier conducting FeAs layer and carrier blocking Sr2CrO3−δ layer. Polycrystalline Sr2CrFeAsO3−δ samples were prepared by solid-state reaction. The oxygen deficiency (δ) of the samples was determined using an assumption of a linear relation between δ and lattice volume (V). The δ-V relation was based on the V of several nominal compositions of polycrystalline samples with a smaller second phase. An electronic and magnetic phase diagram of Sr2CrFeAsO3−δ that considers δ and temperature (T) was created on the basis of electrical resistivity measurements and 57Fe Mössbauer spectroscopy measurements. A magnetic Fe sublattice of Sr2CrFeAsO3−δ exhibited a stripe-type antiferromagnetic (AFM-s) phase for 0.124 ≤ δ ≤ 0.210 at T < 60 K and an internal magnetic field (Hint) distributed antiferromagnetic (AFM-DH) phase for 0.247 ≤ δ ≤ 0.256 at T < 53 K.
