Compensation temperatures and exchange bias in La1.5Ca0.5CoIrO6

TL;DR

This study investigates the complex magnetic behavior of La1.5Ca0.5CoIrO6, revealing multiple magnetization inversions, weak ferromagnetism, spin glass behavior, and exchange bias effects linked to magnetic phase separation and frustration.

Contribution

It provides new insights into the magnetic phase separation and exchange bias phenomena in La1.5Ca0.5CoIrO6, supported by experimental and electronic structure calculations.

Findings

Observation of up to three magnetization inversions.

Detection of exchange bias effect at low temperatures.

Evidence of magnetic phase separation and frustration.

Abstract

We report on the study of magnetic properties of the La1.5Ca0.5CoIrO6 double perovskite. Via ac magnetic susceptibility we have observed evidence of weak ferromagnetism and reentrant spin glass behavior on an antiferromagnetic matrix. Regarding the magnetic behavior as a function of temperature, we have found that the material displays up to three inversions of its magnetization, depending on the appropriate choice of the applied magnetic field. At low temperature the material exhibit exchange bias effect when it is cooled in the presence of a magnetic field. Also, our results indicate that this effect may be observed even when the system is cooled at zero field. Supported by other measurements and also by electronic structure calculations, we discuss the magnetic reversals and spontaneous exchange bias effect in terms of magnetic phase separation and magnetic frustration of Ir4+ ions located between the antiferromagnetically coupled Co ions.