Field-induced avalanche to the ferromagnetic state in the phase-separated ground state of manganites

TL;DR

This study investigates how applying a magnetic field induces an irreversible, avalanche-like transition from a charge-ordered antiferromagnetic phase to a ferromagnetic phase in phase-separated manganites, revealing the dynamics of this transition.

Contribution

It demonstrates the field-induced avalanche transition in phase-separated manganites and characterizes its irreversible nature and threshold behavior.

Findings

Transition occurs spontaneously after exceeding a threshold field.

The transition is abrupt and irreversible, indicating an avalanche process.

Neutron diffraction confirms the phase change from antiferromagnetic to ferromagnetic.

Abstract

Perovskite manganite compounds such as Pr_(1-x)(Ca_(1-y)Sr_y)_xMn3 can be tuned to exhibit a metastable ground state where two magnetic/crystallographic phases coexist in zero magnetic field. Field-dependent neutron diffraction measurements on both poly- and single-crystal samples with a range of Pr, Ca, and Sr dopings(0.3<x<0.35 and y<0.30) reveal that the charge-ordered, antiferromagnetic phase of the ground state suddenly and irreversibly jumps to the ferromagnetic state. The transition occurs spontaneously at some time after the field is set above a threshold field, indicating that once the transition is initiated an avalanche occurs that drives it to completion.