Itinerant Antiferromagnetism in RuO${}_2$

Abstract

Bulk rutile RuO${}_2$ has long been considered a Pauli paramagnet. Here we report that RuO${}_2$ exhibits a hitherto undetected lattice distortion below approximately 900 K. The distortion is accompanied by antiferromagnetic order up to at least 300 K with a small room temperature magnetic moment of approximately 0.05 ${\mu }_B$ as evidenced by polarized neutron diffraction. Density functional theory plus $U$ (DFT+$U$) calculations indicate that antiferromagnetism is favored even for small values of the Hubbard $U$ of the order of 1 eV. The antiferromagnetism may be traced to a Fermi surface instability, lifting the band degeneracy imposed by the rutile crystal field. The combination of high Néel temperature and small itinerant moments make RuO${}_2$ unique among ruthenate compounds and among oxide materials in general.

accepted in Physical Review Letters

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• Two energy gaps and Fermi surface 'arcs' in NbSe2
• CaCrO3: an anomalous antiferromagnetic metallic oxide
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Cited by in corpus (7)

• Antiferromagnetism in RuO${}_2$ as $d$-wave Pomeranchuk instability
• Electric-Field-Controlled Antiferromagnetic Spintronic Devices
• Nonmagnetic Ground State in RuO${}_2$ Revealed by Muon Spin Rotation
• Spin-Neutral Tunneling Anomalous Hall Effect
• Field-Induced Instability of a Gapless Spin Liquid with a Spinon Fermi Surface
• Interlayer magnetism in Fe3-xGeTe2
• Multiband transport in RuO${}_2$