Magnetooptical Study of Spin-Orientation Phase Transition in $NdFe_3(BO_3)_4$ Single Crystal

TL;DR

This study investigates the magnetic field-induced spin-orientation phase transition in NdFe3(BO3)4 single crystals using magnetooptical birefringence measurements, revealing a first-order transition with hysteresis and constructing the H-T phase diagram.

Contribution

It provides the first detailed magnetooptical analysis of the spin-orientation phase transition in NdFe3(BO3)4, including phase diagram mapping under specific field orientations.

Findings

Identified a first-order spin-orientation phase transition with hysteresis.

Observed pronounced jumps in birefringence related to the phase transition.

Constructed the H-T phase diagram for the crystal.

Abstract

The magnetic field dependences of birefringence in a $NdFe_3(BO_3)_4$ single crystal have been measured in the case where the direction of light propagation coincides with the trigonal crystal axis $C_3$ ($k\|C_3$), and the external magnetic field is oriented along the second-order axis $C_2$ ($H\|C_2$). In the temperature range, in which an incommensurate phase exists with the formation of a long-period antiferromagnetic helix, the strongly pronounced jumps in the field dependence of birefringence are revealed and identified as a firstorder spin-orientation phase transition. The phase transition was accompanied by a hysteresis in the field dependences of birefringence. The $H-T$ phase diagram for a $NdFe_3(BO_3)_4$ single crystal has been plotted in the case where the magnetic field is oriented along the crystal axis $C_2$ ($H\|C_2$).