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@INPROCEEDINGS{Kiefer:1034066,
      author       = {Kiefer, Lara and Wirth, Felix and Bertin, Alexandre and
                      Becker, Petra and Bohatý, Ladislav and Schmalzl, Karin and
                      Stunault, Anne and Alberto Rodríguez-Velamazán, J. and
                      Fabelo, Oscar and Braden, Markus},
      title        = {{C}rystal structure and absence of magnetic order in single
                      crystalline {R}u{O}2},
      reportid     = {FZJ-2024-06887},
      year         = {2024},
      abstract     = {RuO2 initially attracted interest in the field of catalysts
                      and microelectronics, but the recent reportof
                      antiferromagnetic order occurring above room temperature and
                      its identificationas an altermagnetic state boosted
                      activities on this material [1,2,3].The combination of spin
                      splitting otherwise characteristic for ferromagnetic order
                      with the linearmagnon dispersion of an antiferromagnetic
                      system may open the path to applications in spintronicsand
                      magnonics [4].However, even the occurrence of magnetic order
                      in RuO2 was recently questioned by muon andneutron
                      experiments as well as by DFT calculations [5-7] and it was
                      proposed that magnetic orderonly occurs in the presence of
                      vacancies [5].We, therefore, performed polarized and
                      unpolarized neutron diffraction experiments on RuO2
                      crystalsthat were characterized by magnetization and
                      electrical conductance measurements as well asby X-ray
                      diffraction [8].Single crystals were grown by chemical vapor
                      transport using two different transport molecules.In
                      addition a powder sample was obtained by annealing a
                      commercial compound.The neutron experiments were performed
                      on D9, D3 and IN12 and the crystal structure was
                      investigatedon a Bruker D8 venture diffractometer. We were
                      not able to confirm the proposed structuraldistortion in our
                      crystals down to 2K. There are no superstructure reflections
                      [3]breaking the symmetry of the rutile-type structure in the
                      X-ray and long-wave length neutron experiments.Such peaks
                      are observed for short neutron wave lengths but can be
                      attributed to multiplediffraction. The amount of ruthenium
                      vacancies is below a few per cent in our crystals.
                      Polarizedneutron experiments do not indicate magnetic Bragg
                      reflections for the proposed propagation vectorof
                      ⃗k=(0,0,0) [3]. Even magnetic order with a five times
                      smallerordered moment than what is claimed [3] would have
                      yielded significant intensities in our experiment.This
                      antiferromagnetic order can be ruled out in our
                      stoichiometric samples [8].[1] L. Smejkal et al., 2022,
                      Phys. Rev. X 12(3), 031042.[2] L. Smejkal et al., 2022,
                      Phys. Rev. X 12(4), 040501.[3] T. Berjilin et al., 2017,
                      Phys. Rev. Lett. 118, 077201.[4] L. Smejkal et al., 2023,
                      Phys. Rev. Lett. 131, 256703.[5] A. Smolyanyuk et al., 2024,
                      Phys. Rev. B. 109, 134424.[6] M. Hiraishi et al., 2024,
                      Phys. Rev. Lett. 132, 166702.[7] P. Keßler et al., 2024,
                      npj Spintronics 2, 50.[8] L. Kiefer et al., 2024, arXiv,
                      2410.05850.23},
      month         = {Dec},
      date          = {2024-12-11},
      organization  = {Flipper 2024 as a satellite workshop
                       of the ILL/ESS user meeting, Institut
                       Laue-Langevin (ILL) located on the
                       European Photon and Neutron (EPN)
                       campus (France), 11 Dec 2024 - 13 Dec
                       2024},
      subtyp        = {Invited},
      cin          = {JCNS-2 / JARA-FIT / JCNS-ILL},
      cid          = {I:(DE-Juel1)JCNS-2-20110106 / $I:(DE-82)080009_20140620$ /
                      I:(DE-Juel1)JCNS-ILL-20110128},
      pnm          = {632 - Materials – Quantum, Complex and Functional
                      Materials (POF4-632) / 6G4 - Jülich Centre for Neutron
                      Research (JCNS) (FZJ) (POF4-6G4)},
      pid          = {G:(DE-HGF)POF4-632 / G:(DE-HGF)POF4-6G4},
      experiment   = {EXP:(DE-Juel1)ILL-IN12-20150421},
      typ          = {PUB:(DE-HGF)6},
      url          = {https://juser.fz-juelich.de/record/1034066},
}