Electrical and magnetic properties of hole-doped ${\mathrm{Sr}}_{1+\mathit{x}}$${\mathrm{La}}_{1\mathrm{-}\mathit{x}}$${\mathrm{FeO}}_4$

Hole-doped ${\mathrm{Sr}}_{1+\mathit{x}}$ ${\mathrm{La}}_{1\mathrm{-}\mathit{x}}$ ${\mathrm{FeO}}_4$ (0≤x≤0.3) samples were prepared, and electrical transport, magnetic properties and ${}_{}{}^{57}{}_{}{}^{}\mathrm{Fe}$ Mössbauer spectra of the resulting materials were measured. The results were compared with those of hole-doped charge-transfer (CT) insulators. The antiferromagnetic Néel temperature decreased from ∼ 350 to ∼150 K on going from x=0 to 0.3, and dc electrical resistivity at room temperature decreased from ∼${10}^3$ Ω cm for x=0 to ∼${10}^0$ Ω cm for x=0.3. The heavily doped samples showed semiconducting behavior even for x=0.3. Seebeck voltage measurements demonstrated that all the samples were p-type semiconductors. Although the changes in the magnetic properties upon doping were qualitatively similar to the CT insulators such as (La,Sr${)}_2$ ${\mathrm{CuO}}_4$ and (La,Sr${)}_2$ ${\mathrm{NiO}}_4$, the changes in the electrical-transport properties upon doping differed from those in the CT insulators. The origin of these differences is discussed with reference to the changes in the electronic structure upon doping.