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arXiv · 2404.00214

Ferromagnetic state with large magnetic moments realized in epitaxially strained Sr3Ru2O7 films

Ren Oshima·Tatsuto Hatanaka·Shinichi Nishihaya·Takuya Nomoto·Markus Kriener·Takahiro C. Fujita·Masashi Kawasaki·Ryotaro Arita·Masaki Uchida
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Abstract

Technical advancement of oxide molecular beam epitaxy (MBE) has opened new avenues for studying various quantum transport phenomena in correlated transition-metal oxides, as exemplified by the exotic superconductivity of Sr$_2$RuO$_4$ and quantum oscillations of SrRuO$_3$. On the other hand, film research of another Ruddlesden-Popper strontium ruthenate Sr$_3$Ru$_2$O$_7$ which exhibits a unique quantum phase related to metamagnetism in bulk systems did not progress well. Here we report the fabrication of high-quality Sr$_3$Ru$_2$O$_7$ thin films by oxide MBE and the observation of a strain-induced ferromagnetic ground state. The change in magnetic exchange coupling evaluated by first-principles calculations indicates a systematic relation between the compression of the $c$-axis length and induced ferromagnetism. Giant epitaxial strain in high-quality films will be a key to a comprehensive understanding of the magnetism in Ruddlesden-Popper strontium ruthenates Sr$_{n+1}$Ru$_n$O$_{3n+1}$, which sensitively depends on the ratio of in-plane to out-of-plane Ru-Ru distances.

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Ren Oshima, Tatsuto Hatanaka, Shinichi Nishihaya, Takuya Nomoto, Markus Kriener, Takahiro C. Fujita, Masashi Kawasaki, Ryotaro Arita, Masaki Uchida. 2024-03-30. Ferromagnetic state with large magnetic moments realized in epitaxially strained Sr3Ru2O7 films. https://doi.org/10.1103/physrevb.109.l121113

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