Synthesis of New Layered Oxypnictides Sr2CrO2(FeAs)2

We successfully synthesized new layered iron oxypnictide Sr2CrO2(FeAs)2 by solid-state-reaction techniques. This is the first report on the Fe-substituted Sr2Mn3As2O2-type oxypnictides to our knowledge. A pellet of stoichiometric mixtures of SrO, Cr and FeAs wrapped with tantalum foil was sintered at 900{\deg}C for 96 h. Results of x-ray diffraction measurement and Rietveld refinements show that the structure of the sample belongs to the space group of I4/mmm with the lattice constants of a = 3.9948(1) {\AA} and c = 18.447(1) {\AA}. Temperature dependence of the resistivity for Sr2CrO2(FeAs)2 shows semiconductor-like behavior. Additionally, the sample does not exhibit superconducting transition in measurements of resistivity and magnetization even in the low temperature down to 3 K.