Field-induced spin-flip and spin-flop transitions in NdFeO3

TL;DR

This study explores how magnetic field orientation influences complex magnetic phase transitions in NdFeO3, revealing the role of 4f-3d interactions in controlling spin states for potential spintronic applications.

Contribution

It demonstrates the field-driven magnetic phase sequences and the impact of 4f-3d anisotropic coupling in NdFeO3, with detailed spectroscopic and thermodynamic analysis.

Findings

Field orientation affects magnetic phase transitions.

Complex spin-flop and spin-flip processes observed.

Nd-sublattice ordering modifies low-temperature transitions.

Abstract

Magnetic control of correlated spin systems is central to the development of next-generation spin-based technologies. Rare-earth orthoferrites provide an interesting platform in which exchange coupling between rare-earth 4f and transition-metal 3d moments generates competing magnetic interactions and multiple metastable states. Here, we show that the orientation of the applied magnetic field drives different magnetic phase transition sequences in NdFeO3 across a broad temperature range. Using Raman and polarized terahertz spectroscopies, supported by magnetization and specific-heat measurements, we track the temperature- and field-dependent evolution of the different magnetic phases and the successive spin rearrangements, driven by 4f - 3d magnetic anisotropic interactions. For fields applied along the crystallographic c-axis, a spin-reorientation transition is followed by spin-flop and spin-flip processes, producing an unexpectedly complex magnetic phase sequence at low temperatures. Below 8 K, precursor effects associated with ordering of the Nd-sublattice strongly modify the transition pathway. Our results demonstrate how anisotropic 4f-3d coupling enables magnetic-field control of coupled spin excitations and provide a route to accessing novel spin configurations in rare-earth orthoferrites.