Pressure induced collapse of magnetic order in jarosite

Abstract

We report a pressure-induced phase transition in the frustrated kagom\'e material jarosite at ~45 GPa, which leads to the disappearance of magnetic order. Using a suite of experimental techniques, we characterize the structural, electronic, and magnetic changes in jarosite through this phase transition. Synchrotron powder X-ray diffraction and Fourier transform infrared spectroscopy experiments, analyzed in aggregate with the results from density functional theory calculations, indicate that the material changes from a R-3m structure to a structure with a R-3c space group. The resulting phase features a rare twisted kagom\'e lattice in which the integrity of the equilateral Fe3+ triangles persists. Based on symmetry arguments we hypothesize that the resulting structural changes alter the magnetic interactions to favor a possible quantum paramagnetic phase at high pressure.