"Investigating the Physical Properties of Transition Metal Oxides with Resonant Elastic and Inelastic X-ray Scattering"
Shih-Wen Huang, Lawrence Berkeley National Laboratory
Thursday, September 12, 2013, 10 am
Seminar Room, Bldg. 725
Hosted by: Ignace Jarrige
I am going to present studies of the electronic structure of complex oxides based on the use of two types of soft x-ray scattering techniques, elastic and inelastic. In the first part of my talk, I will show our recent resonant soft x-ray scattering (RSXS) results on manganites to illustrate the potential of this technique in exploring the static and dynamics electronic orderings. Tracking the field-dependence of ordering peak of TbMnO3 gives the direct view on the manipulation of magnetic order and domain population through in-situ application of electric field. By measuring the magnetic (0 q 0) and the orbital (0 2q 0) reflections with circularly polarized light, we have identified the important role played by magneto-electric orbital moment in the ferroelectric phase. By employing the ultrafast optical pump ��" soft x-ray probe technique, we have observed two intrinsic time scales in the recovery of transient charge order state of La7/8Sr1/8MnO3. The fast time scale, on the order of hundreds of picoseconds, is associated with the reestablishment of charge order domains while the much slower time scale, exceeding microseconds, is relevant to the slower growth of charge order domains. In the second part of my talk, I will present ultrahigh energy resolution M-edge RIXS spectroscopy on CoO and SrCuO2. High energy resolution, comparable to the thermal energy scale, allows the observation of anti-Stokes like feature on the energy gain side of dd excitations for the first time. Such feature is caused by transitions to thermally populated excited states. We also observed a 2-slits-analog of scattering phase interference patterns in the orbiton spectrum of SrCuO2. The potential of employing ultrahigh resolution RIXS to study other correlated systems will be discussed.