Mandal, P and Ojha, SK and Wang, D and Patel, RK and Kumar, S and Maity, J and Zhang, Z and Zhou, H and Klewe, C and Shafer, P and Sanyal, B and Middey, S (2023) Orthorhombic distortion drives orbital ordering in the antiferromagnetic 3d1 Mott insulator PrTiO3. In: Physical Review B, 108 (4).
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Abstract
The orbital, which represents the shape of the electron cloud, very often strongly influences the manifestation of various exotic phenomena, e.g., magnetism, metal-insulator transition, colossal magnetoresistance, unconventional superconductivity, etc. in solid-state systems. The observation of the antiferromagnetism in RETiO3 (RE=rare-earth) series has been puzzling since the celebrated Kugel-Khomskii model of spin-orbital superexchange predicts ferromagnetism in an orbitally degenerate d1 system. Further, the existence of the orbitally ordered vs. orbital liquid phase in both antiferromagnetic and paramagnetic phase have been unsettled issues thus far. To address these longstanding questions, we investigate single crystalline film of PrTiO3. Our synchrotron x-ray diffraction measurements confirm the retention of bulklike orthorhombic (D2h) symmetry in the thin film geometry. We observe similar x-ray linear dichroism signal in both paramagnetic and antiferromagnetic phase, which can be accounted by ferro-orbital ordering (FOO). While the presence of D2h crystal field does not guarantee lifting of orbital degeneracy always, we find it to be strong enough in these rare-earth titanates, leading to the FOO state. Thus, our work demonstrates the orthorhombic distortion is the driving force for the orbital ordering of antiferromagnetic RETiO3.
| Item Type: | Journal Article |
|---|---|
| Publication: | Physical Review B |
| Publisher: | American Physical Society |
| Additional Information: | The copyright for this article belongs to the Authors. |
| Keywords: | Dichroism; Metal insulator boundaries; Metal insulator transition; Mott insulators; Orbits; Paramagnetism; Rare earths; Semiconductor insulator boundaries, Antiferromagnetic phasis; Antiferromagnetics; Electrons clouds; Metal-insulators transitions; Mott insulators; Orbital order; Orbitals; Orthorhombic distortion; Paramagnetic phasis; Unconventional superconductivity, Antiferromagnetism |
| Department/Centre: | Division of Physical & Mathematical Sciences > Physics |
| Date Deposited: | 29 Nov 2023 09:27 |
| Last Modified: | 29 Nov 2023 09:27 |
| URI: | https://eprints.iisc.ac.in/id/eprint/82905 |
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