Systematic Studies of the Surface Structural and Physical Properties in Ca2-xSrxRuO4(

Submitted to the University of Tennessee Comprehensive Exam: Proposal for the Original Research Biao Hu Sep 24 2007 Abstract Transition metal oxides (TMOs) attract extensive attention due to the strong coupling between charge, lattice, orbital, and spin, which results in a variety of exotic phenomena. The Ruddlesden-Popper (RP) (Sr,Ca)n+1RunO3n+1 series are proto-type of strong correlated systems. Due to their layered structures, crystals can be cleaved to create a surface, ideal for studying surface physics. The breaking of the symmetry at the surface will trigger distinct surface phases due to the lattice distortions at the surface. This project will focus on the surface structural and physical properties of Ca2-xSrxRuO4 and Sr3(Ru1-yMny)2O7 while the surface structure can be determined by Low Energy Electron Diffraction (LEED). The surface phonon modes will be probed by High Resolution Electron Energy Loss Spectroscopy (HREELS). Scanning Tunneling Microscopy (STM) and Spectroscopy (STS) will allow us to study the topography and spectroscopy versus temperature and doping level. The doping dependence of the surface structural and physical properties of Ca2-xSrxRuO4 and Sr3(Ru1-yMny)2O7 will be systematically investigated.