Magnetic Phase Transitions in the NdFe_3(BO_3)_4 multiferroic

TL;DR

This study investigates magnetic phase transitions in NdFe_3(BO_3)_4 using acoustic measurements, revealing a first-order transition to an incommensurate spiral phase and constructing phase diagrams with a developed phenomenological theory.

Contribution

It provides new insights into the magnetic phase behavior of NdFe_3(BO_3)_4, including the first observation of a transition to an incommensurate spiral phase and phase diagram construction.

Findings

Detection of magnetic transition at T_N ≈ 30.6 K

Evidence for a first-order transition to an incommensurate spiral phase

H-T phase diagrams for H parallel to a and b axes

Abstract

Low temperature studies of the behavior of the sound velocity and attenuation of acoustic modes have been performed on a single crystal NdFe_3(BO_3)_4. Transitions of the magnetic subsystem to the antiferromagnetically ordered state at T_N \approx 30.6 K have been revealed in the temperature behavior of the elastic characteristics. The features in the temperature behavior of elastic characteristics of the neodymium ferroborate and its behavior in the external magnetic field, applied in the basic plane of the crystal, permit us to suppose that the transition to an incommensurate spiral phase is realized in the system. This phase transition behaves as the first order one. H-T phase diagrams for the cases H \parallel a and H \parallel b have been constructed. The phenomenological theory, which explains observed features, has been developed.