Magnetic and Electronic properties of Eu0.9Ca0.1BaCo2O5.5+? with the disparity of Oxygen Stoichiometry

TL;DR

This study investigates how varying oxygen content influences the magnetic and electronic properties of Eu0.9Ca0.1BaCo2O5.5+δ, revealing complex magnetic behavior and p-type conductivity across different oxygen stoichiometries.

Contribution

It uncovers the paradoxical decrease in Curie temperature with increased oxygen content and supports the magnetic phase separation scenario in calcium-doped cobaltites.

Findings

Curie temperature decreases with higher oxygen content.

All samples exhibit p-type conductivity.

Evidence of Co3+ disproportionation and magnetic phase separation.

Abstract

The effect of oxygen content on the magnetic and transport properties of the ferromagnetic Eu0.9Ca0.1BaCo2O5.5+{\delta} has been carried out. Unlike the increase in TC with calcium content, paradoxally the TC value decreases with the increase in oxygen (Co4+) content as observed in the undoped phase. This result unveils the hidden generic magnetic feature of the LnBaCo2O5.5 system in the calcium doped phase. This behaviour supports strongly the appearance of Co3+ disproportion action into Co4+ and Co2+ and the magnetic phase separation scenario of ferromagnetic domains embedded in an antiferromagnetic matrix. All the samples covering a wide range of oxygen content, exhibit a p-type conductivity.