The identification of electronic states and the analysis of their evolution with n is key to understanding n-layered ruthenates. To this end, we combine polarization-dependent O 1s x-ray absorption spectroscopy, high-purity Sr n+1 Ru n O 3n+1 (n = 1,2,3) single crystals, and ab initio and many-body calculations. We find that the energy splitting between the empty x 2 − y 2 and 3z 2 − 1 state is considerably smaller than previously suggested and that, remarkably, Sr bands are essential to understanding the spectra. At low energy, we identify the main difference among the materials with a substantial rearrangement of t 2g orbital occupations with increasing n. This rearrangement is controlled by the interplay of Coulomb repulsion, dimensionality, and changes in the t 2g crystal field.

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We report a magnetization study down to 1.7 K for the trilayered ruthenate Sr 4 Ru 3 O 10 for magnetic fields applied within the ab plane. Our measurements reveal that the metamagnetic jump appearing in the isothermal magnetization curves below T M = 68 K is actually composed of two consecutive metamagnetic transitions, where the increase in the magnetization due to the second transition is roughly one third of the overall metamagnetic jump. We show that the metamagnetic critical fields for these two transitions increase as the temperature decreases, and that their difference has a weak temperature dependence that opens up in the proximity of the critical region near T M . We discuss the origin of this double metamagnetic transition being due to either the ordering of the Ru 4d magnetic moments in the two inequivalent crystallographic Ru sites or to the presence of two van Hove singularities in the near-Fermi-level density of states.

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We present an angle-resolved photoemission study of the surface and bulk electronic structure of the single layer ruthenate Sr 2 RuO 4 . As the early studies by photoemission and scanning tunneling microscopy were confronted with a problem of surface reconstruction, surface ageing was previously proposed as a possible remedy to access the bulk states. Here, we suggest an alternative way by demonstrating that, in the case of Sr 2 RuO 4 , circularly polarized light can be used to disentangle the signals from the bulk and surface layers, thus opening the possibility to investigate many-body interactions both in bulk and surface bands. The proposed procedure results in improved momentum resolution, which enabled us to detect an unexpected splitting of the surface β band. We discuss the origin of the splitting of the β band and the possible connection with the Rashba effect at the surface. 6 Present address: Diamond

We investigate the electronic structure of the Sr n+1 Ru n O 3n+1 family (n = 1,2,3) in the vicinity the Fermi level by means of polarization-dependent resonant O 1s x-ray emission spectroscopy. Using both energy window and polarization analysis we disentangle the contribution of apical and planar oxygen, and compare it with first-principles calculations. Our results provide a new insight on the nature of the oxygen bonds and the role of Sr 3d states.

Mn substituted MnxZn1−xCo2O4 (x = 0, 0.3, 0.5, 0.7, 1) oxides were synthesized by a facile co-precipitation method followed by calcination at 600 °C.