Magnetic and Electronic Phase Diagram of Sr$_{2}$VFeAsO$_{\mathrm{3-d}}$

Ae$_{2}$MFePnO$_{3}$ (so-called 21113 systems) with perovskite-type layers such as Ae$_{2}$MO$_{3}$, where Ae denotes alkaline earth metals, M does Sc, Ti, Cr, V and other transition metal atoms and Pn does As and P shows superconductivity at T \textless 46 K. Sr$_{2}$VFeAsO$_{\mathrm{3-d}}$ is a representative compound in 21113 systems. [Zhu et al, Phys. Rev. B (2009); Ogino et al, Supercond. Sci. Technol. (2009); Ogino et al, Supercond. Sci. Technol. (2009)] Although the oxygen deficiency (d) as a function of $T_{\mathrm{c}}$ is still controversial in Sr$_{2}$VFeAsO$_{\mathrm{3-d}}$, many samples have been reported as superconductors with $T_{\mathrm{c}} =$ 24-37 K. In this study, a polycrystalline Sr$_{2}$VFeAsO$_{\mathrm{3-d}}$ (d $=$ $\sim$ 0.1- 0.6) were prepared by a solid state reaction using an alumina tube in a sealed silica tube. DC electrical resistivity was measured by a four-probe technique. Magnetization measurements were performed on a superconducting quantum interference device. $^{57}$Fe Mossbauer spectra were obtained using conventional equipment. The electronic and magnetic phase diagram of Sr$_{2}$VFeAsO$_{\mathrm{3-d}}$ is elucidated.