Geometric magnetic frustration in RE2O2S oxysulfides (RE = Sm, Eu and Gd)

• We prepared monophasic RE2O2S Oxysulfides (RE = Sm, Eu and Gd).
• RE2O2S compounds were characterized regarding structural and magnetic properties.
• Mössbauer spectra were obtained for Eu2O2S and Gd2O2S at different temperatures.
• Oxysulfides present geometric magnetic frustration of the rare-earth sublattice.

RE2O2S oxysulfides (with RE = Sm, Eu and Gd) were prepared and characterized regarding their structural and magnetic properties. The compounds crystallized in the trigonal symmetry (space group P-3m/D33d), with the lattice parameter varying linearly with the ionic radius of the RE cation. All these oxysulfides are magnetically frustrated and only the gadolinium sample showed magnetic order down to 3 K. The magnetic frustration is attributed to the spatial distribution of cations over the lattice, where the RE’s magnetic moments occupy the sites forming a triangular plane lattice, perpendicular to the direction. This geometric magnetic frustration was firstly recognized for these oxysulfides.

Stacked planes in the <001> direction of an oxysulfide structure, showing the triangular nets formed by rare earth cations, which moments present geometric magnetic frustration.Figure optionsDownload as PowerPoint slide