Evolution of competing magnetic order in theJeff=1/2insulating state ofSr2Ir1−x

Abstract

We investigate the magnetic properties of the series Sr2Ir1−xRuxO4 with neutron, resonant x-ray and magnetization measurements. The results indicate an evolution and coexistence of magnetic structures via a spin flop transition from ab-plane to c-axis collinear order as the 5d Ir 4+ ions are replaced with an increasing concentration of 4d Ru 4+ ions. The magnetic structures within the ordered regime of the phase diagram (x<0.3) are reported. Despite the changes in magnetic structure no alteration of the J eff =1/2 ground state is observed. The behavior of Sr2Ir1−xRuxO4 is consistent with electronic phase separation and diverges from a standard scenario of hole doping. The role of lattice alterations with doping on the magnetic and insulating behavior is considered. The results presented here provide insight into the magnetic insulating states in strong spin-orbit coupled materials and the role perturbations play in altering the behavior.

Magnetic ground state ofSr2IrO4and implications for second-harmonic generation

“…This feature has been confirmed in several other nonstoichiometric compounds [19,45,46]. Initially interpreted as definitive evidence for this Kramers doublet [9], the absence of a magnetic signal at the L 2 edge was considered as inconclusive, because an in-plane magnetic moment could lead to the same conclusion [43] even if the octahedral limit was not realized.…”

“…Initially interpreted as definitive evidence for this Kramers doublet [9], the absence of a magnetic signal at the L 2 edge was considered as inconclusive, because an in-plane magnetic moment could lead to the same conclusion [43] even if the octahedral limit was not realized. However, the fact that for some doped samples the magnetic moments point out of the xy-plane and the magnetic RXS intensity at the Ir L 2 edge was still strongly depleted [45,46] represent yet another hint towards the physical realization of an octahedral Kramers doublet. However, as this last mentioned experimental evidence referred to Ru-doped [46] and Mn-doped [45] We want to show here, by revisiting some of the calculations, that direct experimental evidence for the realization of this Kramers doublet in Sr 2 IrO 4 is possible, looking at the Ir L 2 edge by X-ray absorption in partial yield in such a way as to reduce the core-hole lifetime to a value below 2 eV.…”

“…However, the fact that for some doped samples the magnetic moments point out of the xy-plane and the magnetic RXS intensity at the Ir L 2 edge was still strongly depleted [45,46] represent yet another hint towards the physical realization of an octahedral Kramers doublet. However, as this last mentioned experimental evidence referred to Ru-doped [46] and Mn-doped [45] We want to show here, by revisiting some of the calculations, that direct experimental evidence for the realization of this Kramers doublet in Sr 2 IrO 4 is possible, looking at the Ir L 2 edge by X-ray absorption in partial yield in such a way as to reduce the core-hole lifetime to a value below 2 eV. The reason is due to the fact that two low-lying empty states are present in the spectrum: the empty partner of the Kramers doublet, within 1 eV of the Fermi level, and the e g states (around ∼ 3 eV above the Fermi level).…”

Structural evolution and electronic properties of (Sr1−xCax)2−yIrO4+

“…iridates. These range from the emergence of nearby competing magnetic states in hole-doped Sr-214, 45,46 to electronic phase separation in hole-doped Sr 3 Ir 2 O 7 , 47 to negative electronic compressibility in electron-doped Sr 3 Ir 2 O 7 .…”

Strong anisotropy within a Heisenberg model in the Jeff=12 insulating state of Sr2Ir0.8Calder1, Kim2, Taylor3 et al. 2016Phys. Rev. BSelf Cite7040View full textAdd to dashboardCite

“…This was achieved throughout the Brillouin zone by assuming L independence, in-line with previous RIXS measurements performed 2,12,13,20 was grown and characterized as described in Ref. 18. The initial 9-ID measurements, with a resolution of E=90 meV FWHM, were used to follow higher energy excitations involving d-d transitions.…”