Neutron scattering evidence for magnetic field driven abrupt magnetic and structural transitions in a phase separated manganite

TL;DR

This study uses neutron diffraction and scattering to reveal how magnetic and structural transitions in a phase-separated manganite are driven by magnetic fields, showing nucleation of ferromagnetic domains and abrupt magnetization jumps.

Contribution

It provides new neutron scattering evidence linking magnetic field-induced transitions to structural changes and domain nucleation in a specific manganite compound.

Findings

Magnetic and structural transitions occur abruptly at certain magnetic fields.

Nucleation of micron-sized ferromagnetic domains is observed.

Transitions are associated with complex antiferromagnetic order.

Abstract

Substitutions at the Mn-site of the charge-ordered Pr0.5Ca0.5MnO3 manganite is an effective way to induce abrupt jumps on the magnetic field driven magnetization curve. In order to get new insights into the origin of this remarkable feature, the Pr0.5Ca0.5Mn0.97Ga0.03O3 perovskite manganite has been studied by neutron diffraction, versus temperature and at 2.5K in an applied magnetic field up to 6 Tesla. A weak and complex antiferromagnetic order is found for the low temperature ground-state. Magnetic transitions, associated with structural ones, are evidenced for certain strengths of magnetic field, which gives rise to the step-like behavior corresponding to the magnetization curve. Small angle neutron scattering provides evidence for a nucleation process of micron size ferromagnetic domains which follows the magnetization behavior.