Origin of the anomalous low-temperature phase transition in BaVS3

Abstract

The origin of the anomalous electronic phase transition (T X ≈ 30 K) caused by a single-electron-occupied t 2g orbital in quasi-one-dimensional BaVS 3 is studied by means of resonant soft x-ray diffraction taken at the V L 2,3 absorption edges. The energy and azimuthal angle dependence of the observed (0 k l) reflection can be explained by the presence of at least two electronically different V contributions. Moreover, analysis of the scattered x-ray polarization indicates that the observed reflection is purely magnetic in origin, which discourages models with orbital and charge modifications occurring at T X. The dependence of the reflection on left or right circular polarized incoming x rays indicates that the incommensurability of the reflection is connected to a helical component of the magnetic structure. These results, together with those from neutron scattering, are discussed in terms of the different models proposed for the electronic and magnetic ground state.

Dzyaloshinskii-Moriya driven helical-butterfly structure in Ba3NbFe3Si2OScagnoli1, Huang2, Garganourakis3 et al. 2013Phys. Rev. BSelf Cite

“…Such scenario cannot be discarded altogether as the odd reflection intensities are between two and three orders of magnitude smaller compared to other magnetic ordering signal found in oxides. 32,34,[48][49][50][51][52][53] It was unfortunately not possible to collect the azimuthal angle dependence of the (0, 0, 3τ ) reflection due to the weakness of the signal.…”

Magnetic phase boundary of BaVS3 clarified with high-pressure μ+SR

“…For the cycloidal IC-SDW, the propagation vector is in the same ab plane as the rotating moments. Furthermore, recent resonant soft XRD measurements suggested the presence of two magnetically different V ions in the lattice [34], leading to a more complex IC-AF structure than that simulated in Fig. 3.…”

Local probing of multiferroics: First-principles study of hyperfine parameters in YMnO3and YMn2O5

“…YMn2O5 is a multiferroic below TC = 39K, where the polarization is induced by a change of magnetic order, from an incommensurate to a commensurate phase [15,16]. The MnO6 octahedra form infinite chains along one direction and share edges with other octahedra in the perpendicular plane.…”