Conference Presentation (Invited)

FZJ-2026-02110

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Magnetic structure and magnetic excitations of the triple layer Sr4Ru3O10

Kiefer, L. ; Ghazinezhad, Z. ; Wirth, F. ; Mettler, J. ; Bengaard Hansen, U. ; Steffens, P. ; Zaharko, O. ; Pomjakushin, V. ; Schmalzl, K. ; Androja, D. ; Nugroho, A. A. ; Braden, M.

2026

Abstract: The triple-layer transition-metal oxide Sr4Ru3O10 is a member of theRuddlesden-Popper series with a layered orthorhombic structure. It is a ferromagneticmetal (TC=105 K) with an additional metamagnetic transition below60 K.The nature of the intermediate phase is still under debate. Using multipleneutron diffraction techniques, we were able to determine its magnetic structure.Our inelastic neutron experiments revealed a parabolic, isotropic dispersionwith a stiffness constant comparable to that of SrRuO3 [1,2]. However, thespin-wave scattering at low constant energy transfer deviates from the expectedisotropic ring, and the stiffness increases upon heating, mirroring SrRuO3 [1,2].Polarized neutron measurements reveal longitudinal spin excitations inside theferromagnetic phase. These amplitude-type fluctuations are unexpected in astandard Heisenberg ferromagnet, suggesting the emergence of a new class ofmagnetic excitations beyond conventional transverse magnons. [1] K. Jenni etal., Phys. Rev. B 107, 174429 (2023). [2] K. Jenni et al., Phys. Rev. Lett. 123,017202 (2019).

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Contributing Institute(s):

1. Streumethoden (JCNS-2)
2. JARA-FIT (JARA-FIT)
3. JCNS-ILL (JCNS-ILL)

Research Program(s):

1. 632 - Materials – Quantum, Complex and Functional Materials (POF4-632) (POF4-632)
2. 6G4 - Jülich Centre for Neutron Research (JCNS) (FZJ) (POF4-6G4) (POF4-6G4)

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