Structure and Physical properties of New layered oxypnictides $Sr_4Sc_2O_6M_2As_2$ (M=Fe and Co)

TL;DR

This study reports the synthesis and characterization of new layered oxypnictides, revealing their structural similarity to known compounds and suggesting potential as new parent materials for iron-based superconductors.

Contribution

The paper introduces new layered oxypnictides with detailed structural and property analysis, proposing them as potential parent compounds for iron-based superconductivity.

Findings

Successful synthesis of $Sr_4Sc_2O_6M_2As_2$ (M=Fe, Co)

Structural similarity to known compounds

Complex transport and magnetic behavior indicating potential superconductivity

Abstract

We have successfully prepared the new layered oxypnictides $Sr_4Sc_2O_6M_2As_2$ (M=Fe and Co). They adopt the tetragonal structure, being the same as that of $Sr_4Sc_2O_6Fe_2P_2$. The lattice constants are a=0.4045 nm and c= 0.5802 nm for M=Fe, and a=0.4045 nm and c=1.5695 nm for M=Co, respectively. Their transport and magnetic properties have been systematically studied. The temperature dependence of Hall coefficient and thermoelectric powder for $Sr_4Sc_2O_6Fe_2As_2$ compound show complicated behavior, similar to that of iron-based parent compounds LnOFeAs and $BaFe_2As_2$. It suggests that the $Sr_4Sc_2O_6Fe_2As_2$ could be considered a new parent compound as iron-based superconductors.