Probing magnon dispersion through inelastic neutron scattering on SrRuO3 thin films
Sagar Mal Kumawat1*, G. D. Dwivedi1, C.-M. Wu2,3, Bo-Yu Chen1, S. T. Lin1, W.-Z. Qiu1, S. J. Sun1,4, Guangyong Xu5, J. W. Lynn5, J. W. Chiou4, C.-H Lee6, W.-H. Li6, S. Yano2,3, H. Chou1,4
1Department of Physics, National Sun Yat-sen University, Kaohsiung City, Taiwan
2National Synchrotron Radiation Research Center, Hsinchu, Taiwan
3Australian Nuclear Science and Technology Organization, New South Wales, Australia
4Department of Applied Physics, National University of Kaohsiung, Kaohsiung, Taiwan
5NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA
6Department of Physics, National Central University, Taoyuan City, Taiwan
* Presenter:Sagar Mal Kumawat,
We successfully observed a magnon peak in SrRuO3 film system with mass 0.9 mg, which is an incredibly small amount to detect magnon signals. Previous reports regarding magnon detections were done on polycrystalline bulk (73 g) or single crystal (6 g) samples [1,2]. Inelastic neutron scattering probe of SIKA at ANSTO, Australia is employed to investigate the magnon profile on SrRuO3 film epitaxially grown on SrTiO3(001) substrate. We observed a major magnon dispersion curve along [002] direction which follows quadratic (E ∝ Q2) relation. A narrow magnon gap of 0.32 meV is obtained from the dispersion curve which is significantly smaller than 2 meV [1] and 1 meV [2] obtained for polycrystalline and single-crystalline samples, respectively. Here, we have presented a few possible mechanisms such as higher symmetry structure and impurity states, which could influence the magnon gap.

Keywords: Inelastic neutron scattering, Magnon gap, Ferromagnetism