Saved in:
| Main Authors: | , , , , , , , , , , |
|---|---|
| Format: | Preprint |
| Published: |
2024
|
| Subjects: | |
| Online Access: | https://arxiv.org/abs/2405.10820 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866909206204907520 |
|---|---|
| author | Keßler, Philipp Garcia-Gassull, Laura Suter, Andreas Prokscha, Thomas Salman, Zaher Khalyavin, Dmitry Manuel, Pascal Orlandi, Fabio Mazin, Igor I. Valentı, Roser Moser, Simon |
| author_facet | Keßler, Philipp Garcia-Gassull, Laura Suter, Andreas Prokscha, Thomas Salman, Zaher Khalyavin, Dmitry Manuel, Pascal Orlandi, Fabio Mazin, Igor I. Valentı, Roser Moser, Simon |
| contents | Altermagnets are a novel class of magnetic materials besides ferro- and antiferromagnets, where the interplay of lattice and spin symmetries produces a magnetic order that is staggered both in coordinate as well as momentum space. The metallic rutile oxide RuO$_2$, long believed to be a textbook Pauli paramagnet, recently emerged as a workhorse altermagnet when resonant X-ray and neutron scattering studies reported nonzero magnetic moments and long-range collinear order. While experiments on thin films seem consistent with altermagnetic behavior, the origin and size of magnetic moments in RuO$_2$ still remain controversial. Here we show that RuO$_2$ is nonmagnetic, regardless if as bulk or thin film. Employing muon spin spectroscopy as a highly sensitive probe of local magnetic moments complemented by density functional theory, we find at most $1.4 \times 10^{-4} $ $μ_B$/Ru in bulk RuO$_2$ and at most $7.5 \times 10^{-4}$ $μ_B$/Ru in epitaxial films. In their essence, these moments reflect the detection limit of our spectrometers and are orders of magnitude smaller than previously reported neutron results, i.e., the moments previously assumed to rationalize altermagnetic behavior. Our own neutron diffraction measurements on RuO$_2$ single crystals identify multiple scattering as a likely source for this discrepancy. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2405_10820 |
| institution | arXiv |
| publishDate | 2024 |
| record_format | arxiv |
| spellingShingle | Absence of magnetic order in RuO$_2$: insights from $μ$SR spectroscopy and neutron diffraction Keßler, Philipp Garcia-Gassull, Laura Suter, Andreas Prokscha, Thomas Salman, Zaher Khalyavin, Dmitry Manuel, Pascal Orlandi, Fabio Mazin, Igor I. Valentı, Roser Moser, Simon Materials Science Altermagnets are a novel class of magnetic materials besides ferro- and antiferromagnets, where the interplay of lattice and spin symmetries produces a magnetic order that is staggered both in coordinate as well as momentum space. The metallic rutile oxide RuO$_2$, long believed to be a textbook Pauli paramagnet, recently emerged as a workhorse altermagnet when resonant X-ray and neutron scattering studies reported nonzero magnetic moments and long-range collinear order. While experiments on thin films seem consistent with altermagnetic behavior, the origin and size of magnetic moments in RuO$_2$ still remain controversial. Here we show that RuO$_2$ is nonmagnetic, regardless if as bulk or thin film. Employing muon spin spectroscopy as a highly sensitive probe of local magnetic moments complemented by density functional theory, we find at most $1.4 \times 10^{-4} $ $μ_B$/Ru in bulk RuO$_2$ and at most $7.5 \times 10^{-4}$ $μ_B$/Ru in epitaxial films. In their essence, these moments reflect the detection limit of our spectrometers and are orders of magnitude smaller than previously reported neutron results, i.e., the moments previously assumed to rationalize altermagnetic behavior. Our own neutron diffraction measurements on RuO$_2$ single crystals identify multiple scattering as a likely source for this discrepancy. |
| title | Absence of magnetic order in RuO$_2$: insights from $μ$SR spectroscopy and neutron diffraction |
| topic | Materials Science |
| url | https://arxiv.org/abs/2405.10820 |