The effect of pressure in the crystal and magnetic structure of FeWO4

TL;DR

This study investigates how high pressure affects the structural and magnetic properties of FeWO4 using neutron diffraction, revealing minor magnetic changes without altering the crystal symmetry up to 8.7 GPa.

Contribution

It provides the first in situ high-pressure neutron diffraction analysis of FeWO4, detailing pressure effects on magnetic orientation and Néel temperature.

Findings

Pressure causes a 5% volume contraction in FeWO4.

Magnetic order's symmetry remains unchanged under pressure.

Pressure slightly modifies magnetic moment orientation and Néel temperature.

Abstract

The temperature dependence of the structural and magnetic properties of wolframite-type FeWO4 were studied in situ by high pressure neutron diffraction. Neutron diffraction measurements were performed at the XtremeD instrument at the Institut Laue Langevin up to a maximum pressure of 8.7(4) GPa and a minimum temperature of 30.0(5) K. The diffraction data were analyzed via Rietveld refinements. We found that despite of producing a contraction of 5% of the volume, the maximum pressure applied in this study does not modify the Shubnikov space group below magnetic order. However, the orientation of magnetic moments and the N\'eel temperature, are slightly modified with the pressure, which is expected according to the preexistent understanding of magnetism in wolframites. We also determined a pressure-volume equation of state of FeWO4 at 300 K, which is compared with previous X-ray diffraction studies and density-functional theory calculations.