Unconventional electronic phases in correlated 5d oxides

CCMMP Seminars
Andrew T Boothroyd
Martin Dove
March 8th, 2016 at 14:00
GO Jones Room 610

In this talk I shall introduce some of the interesting correlated quantum phenomena found recently in iridates and osmates. I shall present the results of neutron and synchrotron X-ray scattering experiments which have been performed to search for a microscopic understanding of the different phases that have been discovered.  In particular, I will describe results for Sr3Ir2O7, which indicate that the behaviour of this material is in between that of a Mott insulator and a correlated metal, and I will present a detailed study of two metallic osmium oxides both of which exhibit structural transitions on cooling that involve a loss of inversion symmetry but each with a distinct mechanism. In LiOsO3, the transition is most likely driven by ordering of Li ion displacements and is “ferroelectric-like”, whereas in Pb2CoOsO6 it is driven by magnetic frustration, analogous to the behaviour of certain type-II multiferroics. These mechanisms could offer a new route to other non-centrosymmetric metallic oxides.