Abstract
The origin of the metal to insulator transition in Fe3O4 remains a challenge due to the complexity of the system: It is a mixed valent, strongly correlated system where many interactions such as Jahn-Teller distortion, exchange, and phonons are very close in energetics. A recent interpretation of the Verwey transition as an ordering of a three-site magnetic polaron, the trimeron, has been put forward. Here we investigate the existence of the trimeron correlations in the high-temperature phase of Fe3O4 using high-resolution iron 2p3d resonant inelastic scattering magnetic linear dichroism. Guided by theoretical simulations, we reveal that the polarization dependence of the low-energy spin-orbital excitations is incompatible with tetragonal Jahn-Teller trimeron-type distortion. We conclude that the lowest-energy state of the high-temperature phase of Fe3O4 arises from an intricate interplay between trigonal crystal-field, exchange, and spin-orbit interactions.
| Original language | English |
|---|---|
| Article number | 085107 |
| Pages (from-to) | 1-5 |
| Journal | Physical Review B |
| Volume | 101 |
| Issue number | 8 |
| DOIs | |
| Publication status | Published - 15 Feb 2020 |
Funding
We thank A. Bosak and M. Hussein for their help with the x-ray-diffraction measurements and sample characterization. A.v.d.E. and S.D. are thanked for their help with designing the sample holder for the synchrotron measurements. We are grateful for the fruitful discussions with A. Juhin, Ch. Brouder, M.-A. Arrio, Ph. Sainctavit, H. Y. Huang, D. J. Huang, and H. Tjeng. We acknowledge the support of the Laue laboratory at the Paul Scherrer Institut (PSI). We thank Thomas Schmidt for his valuable assistance with the experiment. The synchrotron experiments have been performed at the Advanced Resonant Spectroscopies (ADRESS) beamline of the Swiss Light Source at the PSI. The work at PSI is supported by the Swiss National Science Foundation through the National Centres of Competence in Research (NCCR) Materials' Revolution (MARVEL) and the Sinergia network Mott Physics Beyond the Heisenberg Model. M.S. acknowledges support from National Science Center of Poland (Grant No. 2014/14/E/ST3/00026). The research in Dresden is supported by the Deutsche Forschungsgemeinschaft through Grant No. 320571839. This work was financed by the European Research Council XRAYonACTIVE advanced Grant No. 340279.