Related papers: Orbital Dependent Phase Control in Ca2-xSrxRuO4
The electronic structures of the metallic and insulating phases of the alloy series Ca(2-x)Sr(x)RuO4 (0 <= x <= 2) are calculated using LDA, LDA+U and Dynamical Mean-Field Approximation methods. In the end members the groundstate…
The alloy Ca$_{2-x}$Sr$_x$RuO$_4$ exhibits a complex phase diagram with peculiar magnetic metallic phases. In this paper some aspects of this alloy are discussed based on a mean field theory for an effective Kugel-Khomskii model of…
Resonant x-ray diffraction performed at the $\rm L_{II}$ and $\rm L_{III}$ absorption edges of Ru has been used to investigate the magnetic and orbital ordering in Ca$_2$RuO$_4$ single crystals. A large resonant enhancement due to electric…
The nature of the electronic groundstate of Ba2IrO4 has been addressed using soft X-ray absorption and inelastic scattering techniques in the vicinity of the oxygen K edge. From the polarization and angular dependence of XAS we deduce an…
Transition metal oxides exhibit various competing phases and exotic phenomena depending on how their reaction to the rich degeneracy of the $d$-orbital. Large spin-orbit coupling (SOC) reduces this degeneracy in a unique way by providing a…
The effect of isoelectronic substitution within single crystals of (Sr1-xCax)2-yIrO4+z is explored. The nominal n=1 Ruddlesden-Popper phase with y=0, z=0 remains stable from x=0 until x=0.11, where the antiferromagnet spin-orbit Mott…
The electronic and magnetic properties of monoclinic double perovskite Sr$_2$CeIrO$_6$ were examined based on both experiments and first-principles density functional theory calculations. From the calculations we conclude that…
A new concept is proposed for the paramagnetic metal insulator transition in the layer perovskite Ca_{2-x}Sr_xRuO_4. Whereas the pure Sr compound is metallic up to very large Coulomb energies due to strong orbital fluctuations, structural…
The doping and temperature dependent optical conductivity spectra of the quasi-two-dimensional Ca_{2-x}Sr_xRuO_4 (0.0=<x=<2.0) system were investigated. In the Mott insulating state, two electron correlation-induced peaks were observed…
Re-based double perovskites (DPs) exhibit a complex interplay of structural and metal-insulator transitions. Here we systematically study the ground state electronic and structural properties for a family of Re-based DPs $A_2B$ReO$_6$…
Double-perovskite oxides that contain both 3d and 5d transition metal elements have attracted growing interest as they provide a model system to study the interplay of strong electron interaction and large spin-orbit coupling (SOC). Here,…
A lightly doped perovskite mangantite La_{0.88}Sr_{0.12}MnO_3 exhibits a phase transition at T_{OO}=145 K from a ferromagnetic metal (T_C=172 K) to a novel ferromagnetic insulator.We identify that the key parameter in the transition is the…
The magnetic structure and electronic groundstate of the layered perovskite Ba2IrO4 have been investigated using x-ray resonant magnetic scattering (XRMS). Our results are compared with those for Sr2IrO4, for which we provide supplementary…
In strongly correlated electronic systems, several novel physical properties are induced by the orbital degree of freedom. In particular, orbital degeneracy near the Fermi level leads to spontaneous symmetry breaking, such as the nematic…
The double perovskite Ba$_{2}$NaOsO$_{6}$ (BNOO), an exotic example of a very high oxidation state (heptavalent) osmium $d^1$ compound and also uncommon by being a ferromagnetic Mott insulator without Jahn-Teller (JT) distortion, is modeled…
We propose a new mechanism for the paramagnetic metal-insulator transition in the layered perovskite Ca$_{2-x}$Sr$_{x}$RuO$_{4}$ (0<x<0.2). The LDA+U approach including spin-orbit coupling is used to calculate the electronic structures. In…
A spin-orbital superexchange Hamiltonian in a Mott insulator with $t_{2g}$ orbital degeneracy is investigated. More specifically, we focus on a spin ferromagnetic state of the model and study a collective behavior of orbital angular…
The properties of Mott insulators with orbital degrees of freedom are described by spin-orbital superexchange models, which provide a theoretical framework for understanding their magnetic and optical properties. We introduce such a model…
We performed resonant x-ray diffraction experiments at the $L$ absorption edges for the post-perovskite-type compound CaIrO$_{3}$ with $(t_{2g})^5$ electronic configuration. By observing the magnetic signals, we could clearly see that the…
We investigate the electronic and magnetic structures and the character and direction of spin and orbital moments of the recently synthesized quadruple perovskite cobaltovanadate CaCo3V4O12 using a selection of methods from density…