Year: 2021
Type: article
Abstract: A recent polarized neutron diffraction experiment on the $5{d}^{2}$ rhenium double perovskite ${\mathrm{Ba}}_{2}\mathrm{YRe}{\mathrm{O}}_{6}$ held at a low temperature uncovered weak magnetic diffraction peaks. Data analysis inferred a significantly reduced Re dipole moment, and long-range order compatible with an antiferromagnetic, noncollinear motif. To interpret the experimental findings, we present a model wave function for Re ions derived from the crystal field potential, Coulomb interaction, and spin-orbit coupling that fully respects the symmetry of the low-temperature ordered state. It is used to calculate in analytic form all multipole moments visible in neutron and resonance enhanced x-ray diffraction. A minimal model consistent with available neutron diffraction data predicts significant multipolar moments up to the hexadecapole and, in particular, a dominant chargelike quadrupole moment. Calculated diffraction patterns embrace single crystal x-ray diffraction at the Re $L$ edge, and renewed neutron diffraction, to probe the presumed underlying multipolar order.
Language: Latvian
Field: Materials Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W3102145108