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arXiv · 2608.25615

Substitution effects in RuO$_2$ single crystals

Shubhankar Paul·Kunihiko Yamauchi·Shogo Yamashita·Hisakazu Matsuki·Shuhei Iwashita·Mitsuhiko Maesato·Hiroshi Kitagawa·Chanchal Sow·Shingo Yonezawa·Yoshiteru Maeno
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Abstract

RuO$_2$ has emerged as one of the leading candidates for investigating altermagnetism. Recent quantum oscillation and angle-resolved photoemission spectroscopy measurements found the absence of altermagnetism or antiferromagnetism in pure RuO$_2$ crystals. The continuing debate over intrinsic magnetic order in RuO$_2$ may reflect its proximity to an altermagnetic instability. In this work, we grow single crystals of Ru$_{0.9}$V$_{0.1}$O$_2$ and investigate their structural, transport, and magnetic properties. X-ray photoelectron spectroscopy reveals an average V oxidation state near $+4$. The paramagnetic susceptibility remains nearly unchanged up to room temperature, with no evidence of magnetic ordering. Thus, the 10\% V-substitution in RuO$_2$ does not induce altermagnetism. Electronic structure calculations for the V-substituted systems using two methods suggest that a higher level of V-substitution leads to a significant change in the density of states. These findings underscore the potential of nonmagnetic substitution in RuO$_2$ as an attractive candidate for probing altermagnetic transitions and their experimental signatures.

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Shubhankar Paul, Kunihiko Yamauchi, Shogo Yamashita, Hisakazu Matsuki, Shuhei Iwashita, Mitsuhiko Maesato, Hiroshi Kitagawa, Chanchal Sow, Shingo Yonezawa, Yoshiteru Maeno. 2026-08-26. Substitution effects in RuO$_2$ single crystals. https://arxiv.org/abs/2608.25615

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