Effect of the Optical Pumping and Magnetic Field on the States of Phase Separation Domains in Eu_{0.8}Cr_{0.2}Mn_2O_5

TL;DR

This study investigates how optical pumping and magnetic fields influence phase separation domains in Eu_{0.8}Cr_{0.2}Mn_2O_5, revealing a metastable state formation and temperature-dependent recovery of superlattice structures.

Contribution

It demonstrates for the first time that optical pumping induces a metastable state in superlattices, which can be recovered by magnetic field cycling, affecting their thermal stability.

Findings

Optical pumping creates a metastable superlattice state.

Magnetic field cycling can recover the superlattice state.

Recovered superlattices persist at higher temperatures than as-grown crystals.

Abstract

The effect of optical pumping and applied magnetic field on the characteristics of ferromagnetic layers in one-dimensional superlattices is studied. At low enough temperatures, these layers correspond to phase separation domains in RMn_2O_5 and R_{0.8}Ce_{0.2}Mn_2O_5 multiferroics. The formation of such domains occurs owing to the charge ordering of Mn^{3+} and Mn^{4+} ions and to the finite probability for e_g electrons to tunnel between these pairs of ions. The volume occupied by such superlattices is rather small, and they can be treated as isolated ferromagnetic semiconductor heterostructures, spontaneously formed in the host crystal. The sequences of ferromagnetic resonances related to the superlattice layers in Eu_{0.8}Ce_{0.2}Mn_2O_5 are studied. The characteristics of these resonances give information on the properties of such layers. For the first time, it is demonstrated that the optical pumping gives rise to a new metastable state of superlattices, which can be recovered by the magnetic field cycling to the state existing before the optical pumping. It is found that the superlattices recovered by the magnetic field exist up to temperatures higher than those in as-grown crystals.