Local site behavior of the 5d and 4f ions in the frustrated pyrochlore Ho2Os2O7

Abstract

The pyrochlore osmate Ho2Os2O7 is a candidate material for a fragile J=0 local singlet ground state, however little is known regarding the single-ion behavior of either the Os or Ho ions. To address this we present polarized neutron powder diffraction (PNPD) and resonant inelastic x-ray scattering (RIXS) measurements that separately probe the local site behavior of the Os and Ho ions. The PNPD results are dominated by Ho3+ scattering and the analysis reveals local site susceptibility behavior consistent with spin ice materials. Complimentary unpolarized neutron powder diffraction show an ordered spin ice ground state in an applied magnetic field. To isolate the Os4+ single-ion behavior we present resonant inelastic x-ray scattering (RIXS) measurements at the osmium L-edge. Analysis of the RIXS spectra parameterize the spin-orbit coupling (0.35 eV), Hund's coupling (0.27 eV) and trigonal distortion (-0.17 eV). The results are considered within the context of a J=0 model and possible departures from this through structural distortions, excitonic interactions and 5d-4f interactions between the Os ion and the surrounding Ho lattice. The experimental methodology employed highlights the complimentary information available in rare earth based 5d pyrochlores from distinct neutron and x-ray scattering techniques that allow for the isolation and determination of the behavior of the different ions.

References in corpus (9)

• Spin-orbit-entangled electronic phases in 4$d$ and 5$d$ transition-metal compounds
• EDRIXS: An open source toolkit for simulating spectra of resonant inelastic x-ray scattering
• Nonmagnetic $J=0$ State and Spin-Orbit Excitations in K${}_2$RuCl${}_6$
• Local magnetic anisotropy by polarized neutron powder diffraction: application of magnetically induced preferred crystallite orientation
• Ordered spin-ice state in the geometrically frustrated metallic-ferromagnet Sm2Mo2O7
• Competing spin-orbital singlet states in the 4$d^4$ honeycomb ruthenate Ag${}_3$LiRu${}_2$O${}_6$
• Electronic excitations in $5d^4$ J=0 Os${}^{4+}$ halides studied by RIXS and optical spectroscopy
• Spin-orbit excitons and electronic configuration of the $5d^4$ insulator Sr${}_3$Ir${}_2$O${}_7$F${}_2$
• Single crystal growth and magnetism of Sr3NaIrO6 and Sr3AgIrO6: tracking the J = 0 ground state of Ir5+