Oxide electronics

Abstract:

Resonant Elastic X-Ray Scattering (REXS) has played a fundamental role in understanding electronic properties and in revealing hidden order, local symmetries and exotic states realized in correlated solids. This article reports on some of the relevant scientific contributions and technical advances over the last 20 years, by providing a list of related publications produced by various groups all around the world. The given perspective is that of a group of young scientists involved at various times in the investigation of the beauty of electronic ordering by the REXS technique. © 2012 EDP Sciences, Springer-Verlag.

Abstract:

Through powder x-ray diffraction we have investigated the structural behavior of SmVO 3, in which orbital and magnetic degrees of freedom are believed to be closely coupled to the crystal lattice. We have found, contrary to previous reports, that SmVO 3 exists in a single, monoclinic phase below 200 K. The associated crystallographic distortion is then stabilized through the magnetostriction that occurs below 134 K. The crystal structure has been refined using synchrotron x-ray powder diffraction data measured throughout the structural phase diagram, showing a substantial Jahn-Teller distortion of the VO 6 octahedra in the monoclinic phase, compatible with the expected G-type orbital order. Changes in the vanadium ion crystal field due to the structural and magnetic transitions have then been probed by resonant x-ray diffraction. © 2012 American Physical Society.

Abstract:

We have studied the high-temperature multiferroic cupric oxide using polarized neutron diffraction as a function of temperature and applied electric field. We find that the chiral domain population can be varied using an external electric field applied along the b axis. With the aid of representation analysis, we deduce the incommensurate magnetic structure in the multiferroic phase. We conclude that the origin of the magnetoelectric coupling is consistent with recently proposed models which are based on the inverse Dzyaloshinskii - Moriya interaction. © 2012 American Physical Society.