We investigate the frustrated magnetic interactions in cubic transition metal oxides with orbital degeneracy. The eg orbitals order easier and their ordering explains the A-type antiferromagnetic phase in KCuF3 and LaMnO3. In t2g systems the magnetic order changes at a transition from an orbital liquid to orbital ordered states. The fluctuations of t2g orbitals play a prominent role in LaVO3 an...

The preparation of cation-ordered thin films correlated oxides is great interest for both fundamental and applied research. scientific long-term vision strongly motivated by the perspective studying electronic correlations in condensed matter without presence chemical or quenched disorder. A promising material platform provides double perovskite A2BB’O6 bulk samples with different types B/B’ or...

We use the temperature of the structural phase transition to determine the Jahn-Teller (JT) coupling constant in the model derived for LaMnO3 which includes both the superexchange between S = 2 spins and the JT effect. We also investigate the dependence of the exchange constants on the value of the on-site Coulomb element U , and on the orbital ordering. Journal ref.: O. Sikora and A. M. Oleś, ...

A tight binding parameterization of the band structure, along with a mean field treatment of Hund, electron-electron, and electron-lattice couplings, is used to obtain the full optical conductivity tensor of LaMnO3 as a function of temperature. We predict striking changes with temperature in the functional form and magnitude of the optical absorption. Comparison of our results to data will dete...

Orbital excitations have been sought in three systems, LaMnO3, KCuF3 andYTiO3, using high-resolution inelastic x-ray scattering, with an energy resolution of 6 meV. Motivated by the recent Raman scattering result of Saitoh et al (2001 Nature 410 180), we measured the energy transfer spectra of LaMnO3 in the energy range up to 200 meV. We did not find any signal above background that could be as...

The resonant multiple Bragg x-ray diffraction is used to study the forbidden (104) reflection in LaMnO3. Using the interference between the three-beam scattering and resonant scattering we can determine the phase of the resonant scattering. This phase is shown to be consistent with a model in which the resonant scattering is caused by the influence of the Mn-O bond length distortion rather than...

Gold and gold alloys, in the form of supported nanoparticles, have been shown over the last three decades to be highly effective oxidation catalysts. Mixed metal oxide perovskites, with their high structural tolerance, are ideal for investigating how changes in the chemical composition of supports affect the catalysts' properties, while retaining similar surface areas, morphologies and metal co...