Various arsenic network structures in 112-type Ca1-xLaxFe1-yPdyAs2 revealed by synchrotron x-ray diffraction experiments

TL;DR

This study synthesizes and characterizes novel 112-type palladium-doped iron arsenides, revealing diverse arsenic network structures and providing insights into their potential as high-temperature superconductors.

Contribution

It introduces new 112-type iron arsenide compounds with unique arsenic networks and uses synchrotron X-ray techniques to analyze their structures and oxidation states.

Findings

Different arsenic network structures identified in synthesized compounds.

Similar oxidation states around FeAs4 tetrahedra across samples.

Potential parent compounds for high Tc 112-type superconductors suggested.

Abstract

Two novel 112-type palladium doped iron arsenides were synthesized and identified using comprehensive studies involving synchrotron x-ray diffraction and x-ray absorption near edge structure (XANES) experiments. Whereas in-plane arsenic zigzag chains were found in 112-type superconducting iron arsenide, Ca1-xLaxFeAs2 with maximum Tc = 34 K, deformed arsenic network structures appeared in 112-type materials such as longitudinal arsenics zigzag chains in CaFe1-yPdyAs2 (y ~ 0.51) and arsenic square sheets constructed via hypervalent bonding in Ca1-xLaxFe1-yPdyAs2 (x ~ 0.31, y ~ 0.30). As K-edge XANES spectra clarified the similar oxidization states around FeAs4 tetrahedrons, expecting us the possible parents for high Tc 112-type iron arsenide superconductors.