Synthesis, Crystal Structure and Magnetism of Eu3Sc2O5Fe2As2

TL;DR

This study reports the synthesis, crystal structure, and magnetic properties of Eu3Sc2O5Fe2As2, revealing its layered structure, magnetic behavior consistent with Eu2+ ions, and possible antiferromagnetic ordering at low temperatures.

Contribution

It provides the first detailed synthesis, structural characterization, and magnetic analysis of Eu3Sc2O5Fe2As2, expanding understanding of iron arsenide compounds with complex oxide layers.

Findings

Layered structure with FeAs4 tetrahedra and oxide blocks

Magnetic behavior consistent with Eu2+ ions

Possible antiferromagnetic ordering at 5 K

Abstract

The iron arsenide Eu3Fe2O5Fe2As2 was synthesized at 1173-1373 K in a resistance furnace and characterized by X-ray powder diffraction with Rietveld analysis: Sr3Fe2O5Cu2S2-type, I4/mmm, a = 406.40(1) pm, c = 2646.9(1) pm. Layers of edge-sharing FeAs4/4 tetrahedra are separated by perovskite-like oxide blocks. No structural transition occurs in the temperature range from 10 to 300 K. Magnetic measurements have revealed Curie-Weiss behavior with an effective magnetic moment of 7.79 muB per europium atom in agreement with the theoretical value of 7.94 muB for Eu2+. A drop in the magnetic susceptibility at 5 K indicates possible antiferromagnetic ordering. 151Eu and 57Fe M\"ossbauer spectroscopic measurements have confirmed a beginning cooperative magnetic phenomenon by showing significantly broadened spectra at 4.8 K compared to those at 78 K.