Magnetic Uniformity and Limits on Room-Temperature Magnetization in Strained RuO2/TiO2 Films

Published

May 29, 2025

Author(s)

Xuezhao Wu, Alexander Grutter, Ruizi Liu, Purnima P. Balakrishnan, Christy J. Kinane, Andrew J. Caruana, Yiyang Zhang, Xiaolin Ren, Yifan Jiang, Rolf Lortz, Shiming Lei, Qiming Shao

Abstract

Altermagnets attract much attention due to their unique spin-splitting energy band and potential applications in spintronics. Ruthenium oxide (RuO2) has been reported as a metallic altermagnet, exhibiting long-range spin-splitting torque without considerable spin-orbit coupling. However, recently, various independent experimental observations of RuO2, including by angle-resolved photoemission spectroscopy and neutron diffraction, suggest the absence of altermagnetic order and a preference for the nonmagnetic phase in RuO2. Here we investigate the strain relaxation along the thickness of [101]-oriented RuO2 films on TiO2 substrates using x-ray diffraction and analyze the potential nonuniform strain-induced net magnetization profile through superconducting quantum interference device magnetometry and polarized neutron reflectometry (PNR). Four models with different constraints were used to fit the PNR data, revealing no significant net magnetization signal in either the film or the interface. Our findings could contribute to the future clarification of the altermagnetic origins of RuO2.

Citation

Physical Review Applied

Volume

23

Issue

5

Pub Type

Journals

Download Paper

https://doi.org/10.1103/PhysRevApplied.23.054082

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Keywords

Magnetism, Altermagnet, Reflectometry, Thin Film

Citation

Wu, X. , Grutter, A. , Liu, R. , Balakrishnan, P. , Kinane, C. , Caruana, A. , Zhang, Y. , Ren, X. , Jiang, Y. , Lortz, R. , Lei, S. and Shao, Q. (2025), Magnetic Uniformity and Limits on Room-Temperature Magnetization in Strained RuO2/TiO2 Films, Physical Review Applied, [online], https://doi.org/10.1103/PhysRevApplied.23.054082, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=958967 (Accessed July 29, 2025)