Controlling structural distortion in the geometrically frustrated layered cobaltate YBaCo4O7+{\delta} by Fe substitution and its role on magnetic correlations

TL;DR

This study investigates how Fe substitution affects the crystal structure and magnetic properties of the geometrically frustrated layered cobaltate YBaCo4+δO7, revealing reduced distortion and altered magnetic correlations.

Contribution

It provides new insights into controlling structural distortion and magnetic correlations through Fe substitution in layered cobaltates.

Findings

Fe ions occupy both 2a and 6c sites in the structure.

Fe substitution reduces Kagomé lattice distortion.

Magnetic correlation length decreases with Fe content.

Abstract

Effects of Fe-substitution on the crystal structure and magnetic correlations of the geometrically frustrated antiferromagnets YBaCo4-xFexO7+{\delta} (x = 0, 0.2, 0.4, 0.5, 0.6, and 0.8) have been studied by neutron diffraction, M\"ossbauer spectroscopy, and ac susceptibility. The compounds YBaCo4-xFexO7+{\delta} have a special layered-type crystal structure with an alternating Kagom\'e (6c site) and triangular (2a site) layers along the c axis. Fe3+ ions are found to be substituted at both the crystallographic 2a and 6c sites of Co ions. M\"ossbauer results show a high spin state of Fe3+ ions in a tetrahedral coordination. A reduction in the distortion of the Kagom\'e lattice has been observed with the Fe-substitution. The correlation length of the short-range antiferromagnetic ordering decreases with the Fe-substitution. The sharpness of the magnetic transition also decreases with the Fe-substitution.