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A theoretical investigation of a plausible construct for electronic structure in iridate perovskites demonstrates the existence of magnetic multipoles hitherto not identified. The strange multipoles, which are parity-even, time-odd and even rank tensors, are absent from the so-called jeff = 1/2 model. We prove that the strange multipoles contribute to magnetic neutron diffraction, and we estimate their contribution to intensities of Bragg spots for Sr2IrO4. The construct encompasses the jeff = 1/2 model, and it is consistent with the known magnetic structure, ordered magnetic moment, and published resonant x-ray Bragg diffraction data. Over and above time-odd quadrupoles and hexadecapoles, whose contribution changes neutron Bragg intensities by an order of magnitude, according to our estimates, are relatively small triakontadipoles recently proposed as the primary magnetic order-parameter of Sr2IrO4.
A recent polarized neutron diffraction experiment on the 5d2 rhenium double perovskite Ba2YReO6 held at a low temperature uncovered weak magnetic diffraction peaks. Data analysis inferred a significantly reduced Re dipole moment, and long-range order
Structural and magnetic transitions in a double perovskite hosting 5d1 Re ions are discussed on the basis of recently published high-resolution x-ray diffraction patterns [D. Hirai, et al., Phys. Rev. Res. 2, 022063(R) (2020)]. A reported structural
Neutron diffraction measurements on a single crystal of CeGe1.76 reveal a complex series of magnetic transitions at low temperature. At T_N = 7 K, there is a transition from a paramagnetic state at higher temperature to an incommensurate magnetic str
The magnetic ordering of the hexagonal multiferroic compound YbMnO$_3$ has been studied between 100 K and 1.5 K by combining neutron powder diffraction, $^{170}$Yb Mossbauer spectroscopy and magnetization measurements. The Yb moments of the two cryst
$rm Sr_2IrO_4$ is an archetypal spin-orbit-coupled Mott insulator and has been extensively studied in part because of a wide range of predicted novel states. Limited experimental characterization of these states thus far brings to light the extraordi