Resonant Elastic X-Ray Scattering of Antiferromagnetic Superstructures in EuPtSi3

We report resonant elastic x-ray scattering of long-range magnetic order in EuPtSi3, combining different scattering geometries with full linear polarization analysis to unambiguously identify magnetic scattering contributions. At low temperatures, EuPtSi3 stabilizes type A antiferromagnetism featuring various long -wavelength modulations. For magnetic fields applied in the hard magnetic basal plane, well-defined regimes of cycloidal, conical, and fanlike superstructures may be distinguished that encompass a pocket of commensurate type A order without superstructure. For magnetic field applied along the easy axis, the phase diagram comprises the cycloidal and conical superstructures only. Highlighting the power of polarized resonant elastic x-ray scattering, our results reveal a combination of magnetic phases that suggest a highly unusual competition between antiferromagnetic exchange interactions with Dzyaloshinsky-Moriya spin-orbit coupling of similar strength.

Automated summary

We present resonant elastic x-ray scattering results on EuPtSi3, revealing a combination of magnetic phases suggesting a highly unusual competition between antiferromagnetic exchange interactions with Dzyaloshinsky-Moriya spin-orbit coupling of similar strength. By utilizing different scattering geometries and full linear polarization analysis, we unambiguously identify magnetic scattering contributions. The phase diagram of EuPtSi3 includes various long-wavelength modulations and distinct superstructures for different magnetic field orientations.