Non-Resonant X-ray Magnetic Scattering on Rare-Earth Iron Borates RFe$_3$(BO$_3$)$_4$

TL;DR

This study uses hard x-ray scattering to investigate magnetic and structural properties of RFe₃(BO₃)₄ compounds, revealing unexpected diffraction features and detailed magnetic domain structures, advancing understanding of their magnetic behavior.

Contribution

The paper demonstrates non-resonant magnetic reflections and structural anomalies in RFe₃(BO₃)₄, providing new insights into their magnetic structures through x-ray scattering analysis.

Findings

Detection of unexpected non-resonant magnetic reflections

Magnetic domain correlation length around 100 Å

Fe moments rotated approximately 53 degrees from the basal plane

Abstract

Hard x-ray scattering (HXS) experiments with a photon energy of 100keV were performed as a function of temperature and applied magnetic field on selected compounds of the RFe$_3$(BO$_3$)$_4$ family. The results show the presence of several unexpected diffraction features, in particular non-resonant magnetic reflections in the magnetically ordered phase, and structural reflections that violate the diffraction conditions for the low temperature phase $P3_121$ of the rare-earth iron borates. The temperature and field dependence of the magnetic superlattice reflections corroborate the magnetic structures of the borate compounds obtained by neutron diffraction. The detailed analysis of the intensity and scattering cross section of the magnetic reflection reveals details of the magnetic structure of these materials such as the spin domain structure of NdFe$_3$(BO$_3$)$_4$ and GdFe$_3$(BO$_3$)$_4$. Furthermore we find that the correlation length of the magnetic domains is around 100 \AA{} for all the compounds and that the Fe moments are rotated $53^\circ\pm3^\circ$ off from the hexagonal basal plane in GdFe$_3$(BO$_3$)$_4$