85 research outputs found
Complex electronic states in double layered ruthenates (Sr1-xCax)3Ru2O7
The magnetic ground state of (SrCa)RuO (0 1) is complex, ranging from an itinerant metamagnetic state (0
0.08), to an unusual heavy-mass, nearly ferromagnetic (FM) state (0.08
0.4), and finally to an antiferromagnetic (AFM) state (0.4 1). In
this report we elucidate the electronic properties for these magnetic states,
and show that the electronic and magnetic properties are strongly coupled in
this system. The electronic ground state evolves from an AFM
quasi-two-dimensional metal for 1.0, to an Anderson localized state for
(the AFM region). When the magnetic state undergoes a
transition from the AFM to the nearly FM state, the electronic ground state
switches to a weakly localized state induced by magnetic scattering for , and then to a magnetic metallic state with the in-plane
resistivity ( 2) for .
The system eventually transforms into a Fermi liquid ground state when the
magnetic ground state enters the itinerant metamagnetic state for .
When approaches the critical composition ( 0.08), the Fermi liquid
temperature is suppressed to zero Kelvin, and non-Fermi liquid behavior is
observed. These results demonstrate the strong interplay between charge and
spin degrees of freedom in the double layered ruthenates.Comment: 10 figures. To be published in Phys. Rev.
Doping and dimensionality effects on the core-level spectra of layered ruthenates
Core-level spectra of the Mn-doped Sr3Ru2O7 and Srn+1RunO3n+1 (n = 1, 2 and
3) crystals are investigated with X-ray photoelectron spectroscopy. Doping of
Mn to Sr3Ru2O7 considerably affects the distribution of core-level spectral
weight. The satellite of Ru 3d core levels exhibits a substantial change with
doping, indicating an enhanced electron localization across the doping- induced
metal-insulator transition. However, the Ru 3p core levels remain identical
with Mn-doping, thus showing no sign of doping-induced multiple Ru valences. In
the Srn+1RunO3n+1 (n = 1, 2 and 3), the Ru 3d core-level spectra are similar,
indicating that the chemical bonding environment around Ru ions remains the
same for different layered compounds. Meanwhile the Sr 3d shallow core levels
shift to higher binding energy with increasing n, suggesting their
participation in Sr-O bonding with structural evolution.Comment: 6 pages with 6 figures, to be published in PR
Complex electronic states in double layered ruthenates (Sr1-xCax)3Ru2O7
The magnetic ground state of (SrCa)RuO (0 1) is complex, ranging from an itinerant metamagnetic state (0
0.08), to an unusual heavy-mass, nearly ferromagnetic (FM) state (0.08
0.4), and finally to an antiferromagnetic (AFM) state (0.4 1). In
this report we elucidate the electronic properties for these magnetic states,
and show that the electronic and magnetic properties are strongly coupled in
this system. The electronic ground state evolves from an AFM
quasi-two-dimensional metal for 1.0, to an Anderson localized state for
(the AFM region). When the magnetic state undergoes a
transition from the AFM to the nearly FM state, the electronic ground state
switches to a weakly localized state induced by magnetic scattering for , and then to a magnetic metallic state with the in-plane
resistivity ( 2) for .
The system eventually transforms into a Fermi liquid ground state when the
magnetic ground state enters the itinerant metamagnetic state for .
When approaches the critical composition ( 0.08), the Fermi liquid
temperature is suppressed to zero Kelvin, and non-Fermi liquid behavior is
observed. These results demonstrate the strong interplay between charge and
spin degrees of freedom in the double layered ruthenates.Comment: 10 figures. To be published in Phys. Rev.
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