Effect of Oxygen Content on Magnetic Properties of Layered Cobaltites PrBaCo2O5+\delta

TL;DR

This study investigates how varying oxygen content in layered PrBaCo2O5+δ affects its magnetic properties, revealing persistent ferromagnetic interactions across different oxygen levels and temperatures, linked to structural changes around cobalt ions.

Contribution

It provides a detailed magnetic phase diagram for PrBaCo2O5+δ and links magnetic behavior to oxygen content and local structural changes around Co ions.

Findings

Ferromagnetic interactions persist below Tc and in the antiferromagnetic phase.

Short-range ferromagnetic interactions exist above Tc in low oxygen content samples.

Magnetic properties are linked to structural changes around Co ions.

Abstract

The effect of oxygen content on the magnetic properties of the layered perovskites has been investigated. The samples, PrBaCo$_{2}$O$_{5+\delta}$ (0.35 $\leq \delta \leq$ 0.80) were prepared by sol-gel method and characterized by X-ray diffraction and DC magnetization. A detailed magnetic phase diagram for PrBaCo$_{2}$O$_{5+\delta}$ is presented. It is found that unlike in the case of heavier rare-earths, ferromagnetic interactions are present at all temperatures below Tc and even in the antiferromagnetically ordered phase. Moreover, in compounds with lower oxygen content, short range ferromagnetic interactions are present even above Tc. This dependence of magnetic properties on oxygen content in these layered perovskites has been linked to the changes in polyhedra around the Co ions.