Impact of Fe doping on the electronic structure of SrTiO 3 thin films determined by resonant photoemission

Epitaxial thin films of Fe doped SrTiO3 have been studied by the use of resonant photoemission. This technique allowed us to identify contributions of the Fe and Ti originating electronic states to the valence band. Two valence states of iron Fe2+ and Fe3+, detected on the base of x-ray absorption studies spectra, appeared to form quite different contributions to the valence band of SrTiO3. The electronic states within the in-gap region can be attributed to Fe and Ti ions. The Fe2+ originating states which can be connected to the presence of oxygen vacancies form a broad band reaching binding energies of about 0.5 eV below the conduction band, while Fe3+ states form in the gap a sharp feature localized just above the top of the valence band. These structures were also confirmed by calculations performed with the use of the FP-LAPW/APW+lo method including Coulomb correlations within the d shell. It has been shown that Fe doping induced Ti originating states in the energy gap which can be related to the hybridization of Ti and Fe 3d orbitals

Inhomogenous magnetic ground state in CeAgGa

CeAgGa crystallizes in CeCu 2 Imma structure with Ag and Ga atoms randomly distributed at 8h sites. The magnetic and transport properties of the orthorhombic CeAgGa compound have been obtained from the analysis of ac magnetic susceptibility χ ac , magnetization M vs. magnetic field, specific heat C and electrical resistivity ρ. The results provide evidence for the formation of a spin-glass state with a freezing temperature T f =5.1 K. The randomness in the Ce-Ce magnetic exchange interactions seem to arise from a statistical distribution of Ag and Ga atoms on a crystallographic site of the CeAgGa crystal lattice. The results provide also evidence for the formation of ferromagnetic-like order at the temperature T C ≈ 3.6 K. Band structure calculations for a disordered system give magnetic moment similar to saturation moment obtained from magnetization measurements, however, its calculated value is insensitive on Ga/Ag off-stoichiometry in the 8h position. Complex behavior of CeAgGa Kondo-lattice compound is discussed in terms of interplaying Ruderman-Kittel-Kasuya-Yosida (RKKY) interactions, Kondo effect and structural disorder. Copyright EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg 2011

When Opportunity Knocks: Confronting Theory and Empirics About Dynamics of Gender Wage Inequality

We present empirical evidence that large structural shocks are followed by changes in labor market inequality. Specifically, we study short-run fluctuations in adjusted gender wage gaps (unequal pay for equal work) following episodes of structural shocks in the labor markets, using several decades of individual data for a wide selection of transition countries. We find that for cohorts who entered the labor market after the onset of transition. Labor market shocks lead to significant declines in the gender wage gap. This decrease is driven mostly by episodes experienced among cohorts who enter the labor market during the transition. By contrast, we fail to find any significant relation for cohorts already active in the labor market at the time of transition. We provide plausible explanations based on sociological and economic theories of inequality