X-ray scattering study of pyrochlore iridates: crystal structure, electronic and magnetic excitations

Abstract

We have investigated the structural, electronic, and magnetic properties of the pyrochlore iridates Eu2Ir2O7 and Pr2Ir2O7 using a combination of resonant elastic x-ray scattering, x-ray powder diffraction, and resonant inelastic x-ray scattering (RIXS). The structural parameters of Eu2Ir2O7 have been examined as a function of temperature and applied pressure, with a particular emphasis on regions of the phase diagram where electronic and magnetic phase transitions have been reported. We find no evidence of crystal symmetry change over the range of temperatures (~6 to 300 K) and pressures (~0.1 to 17 GPa) studied. We have also investigated the electronic and magnetic excitations in single crystal samples of Eu2Ir2O7 and Pr2Ir2O7 using high resolution Ir L3-edge RIXS. In spite of very different ground state properties, we find these materials exhibit qualitatively similar excitation spectra, with crystal field excitations at ~3-5 eV, spin-orbit excitations at ~0.5-1 eV, and broad low-lying excitations below ~0.15 eV. In Eu2Ir2O7 we observe highly damped magnetic excitations at ~45 meV, which display significant momentum dependence. We compare these results with recent dynamical structure factor calculations.

14 pages, 13 figures (including supplemental material)

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Cited by in corpus (22)

• Recent progress on correlated electron systems with strong spin-orbit coupling
• Weyl magnons in pyrochlore antiferromagnets with all-in-all-out orders
• A magnetic Weyl semimetallic phase in thin films of Eu${}_2$Ir${}_2$O${}_7$
• Topological magnons with nodal-line and triple-point degeneracies: Implications for thermal Hall effect in pyrochlore iridates
• Pressure-driven collapse of the relativistic electronic ground state in a honeycomb iridate
• High-pressure versus isoelectronic doping effect on the honeycomb iridate Na${}_2$IrO${}_3$
• Dilute stuffing in the pyrochlore iridate $E{u}_{2}I{r}_2{O}_7$
• Robust pinning of magnetic moments in pyrochlore iridates
• Structural, electronic, and magnetic properties of nearly-ideal $J_{\mathrm{eff}}$ $=$ 1/2 iridium halides
• Almost pure $J_{\mathrm{eff}}=1/2$ Mott state of In${}_2$Ir${}_2$O${}_7$ in the limit of reduced inter-site hopping
• Direct detection of dimer orbitals in Ba${}_5$AlIr${}_2$O${}_{11}$
• Magnetic and transport properties in pyrochlore iridates (Y${}_{1-x}$Pr${}_x$)${}_2$Ir${}_2$O${}_7$: The role of $f$-$d$ exchange interaction and $d$-$p$ orbital hybridization
• Spin-phonon coupling in hole-doped pyrochlore iridates Y${}_2$(Ir${}_{1-x}$Ru${}_x$)${}_2$O${}_7$: A Raman scattering study
• Evolution of Magnetic Excitations Across the Metal-Insulator Transition in a Pyrochlore Iridate Eu${}_2$Ir${}_2$O${}_7$
• The interplay between structural, magnetic and electronic states in the pyrochlore iridate Eu2Ir2O7
• Approaching the quantum critical point in a highly-correlated all-in-all-out antiferromagnet
• Resonant inelastic x-ray scattering spectra in the hyperhoneycomb iridate $\beta$-Li${}_2$IrO${}_3$: First principles calculations
• Phonon spectrum of Pr${}_2$Zr${}_2$O${}_7$ and Pr${}_2$Ir${}_2$O${}_7$ as an evidence of coupling of the lattice with electronic and magnetic degrees of freedom
• Emergence of weak pyrochlore phase and signature of field induced spin ice ground state in Dy${}_{2-x}$La${}_x$Zr${}_2$O${}_7$; x = 0, 0.15, 0.3
• Nonmagnetic substitution in pyrochlore iridate Y${}_2$(Ir${}_{1-x}$Ti${}_x$)${}_2$O${}_7$: Structure, magnetism and electronic properties
• Selective probing of magnetic order on Tb and Ir sites in stuffed Tb${}_{2+x}$Ir${}_{2-x}$O${}_{7-y}$ using resonant X-ray scattering
• Mapping the structural, magnetic and electronic behavior of (Eu${}_{1-x}$Ca${}_x$)${}_2$Ir${}_2$O${}_7$ across a metal-insulator transition