Enhancement of ferromagnetism by nickel doping in the 112 cobaltite EuBaCo2O5.50

TL;DR

Nickel doping in EuBaCo2O5.50 enhances ferromagnetism, induces phase separation, and reveals new magnetic transitions and domain wall dynamics at low temperatures.

Contribution

This study demonstrates that nickel doping induces ferromagnetic components and phase separation in EuBaCo2O5.50, revealing new magnetic transitions and domain wall behaviors.

Findings

Nickel doping induces ferromagnetism in EuBaCo2O5.50.

A magnetic transition at 40K related to Eu3+ moments.

Observation of ultra-magnetization multisteps below 5K.

Abstract

The study of the ordered oxygen deficient perovskite EuBaCo2-xNixO5.50 shows that the doping of cobalt sites by nickel induces a strong ferromagnetic component at low temperature in the antiferromagnetic matrix of EuBaCo2O5.50. This system exhibits indeed phase separation, i.e. consists of ferromagnetic domains embedded in the antiferromagnetic matrix of EuBaCo2O5.50. Besides, a magnetic transition is observed for the first time at 40K in the undoped and nickel doped phases, which can be attributed to the ferromagnetic ordering of the Eu3+ moments below this temperature. Moreover sharp ultra magnetization multisteps are observed below 5K, characteristic of motion of domain walls in a strong pinning system and very different from any metamagnetic transition.