Field-induced segregation of ferromagnetic nano-domains in Pr$_{0.5}$Sr$_{0.5}$MnO$_3$, detected by $^{55}$Mn NMR

TL;DR

This study investigates how applying a magnetic field induces ferromagnetic domains in Pr$_{0.5}$Sr$_{0.5}$MnO$_3$, revealing a transition from antiferromagnetic to ferromagnetic states through NMR and magnetometry.

Contribution

The paper demonstrates the field-induced formation and evolution of ferromagnetic domains in Pr$_{0.5}$Sr$_{0.5}$MnO$_3$ using $^{55}$Mn NMR, highlighting a percolative transition mechanism.

Findings

Magnetization shows a transition at a few tesla.

NMR detects microscopic ferromagnetic domains nucleating from zero field.

Transition to a homogeneous ferromagnetic state is discontinuous.

Abstract

The antiferromagnetic manganite Pr$_{0.5}$Sr$_{0.5}$MnO$_3$ was investigated at low temperature by means of magnetometry and $^{55}$Mn NMR. A field-induced transition to a ferromagnetic state is detected by magnetization measurements at a threshold field of a few tesla. NMR shows that the ferromagnetic phase develops from zero field by the nucleation of microscopic ferromagnetic domains, consisting of an inhomogeneous mixture of tilted and fully aligned parts. At the threshold the NMR spectrum changes discontinuously into that of a homogeneous, fully aligned, ferromagnetic state, suggesting a percolative origin for the ferromagnetic transition.