TY - JOUR
T1 - Orthorhombic distortion drives orbital ordering in the antiferromagnetic 3d1 Mott insulator PrTiO3
AU - Mandal, Prithwijit
AU - Ojha, Shashank Kumar
AU - Wang, Duo
AU - Patel, Ranjan Kumar
AU - Kumar, Siddharth
AU - Maity, Jyotirmay
AU - Zhang, Zhan
AU - Zhou, Hua
AU - Klewe, Christoph
AU - Shafer, Padraic
AU - Sanyal, Biplab
AU - Middey, Srimanta
N1 - Publisher Copyright:
© 2023 American Physical Society.
PY - 2023/7/15
Y1 - 2023/7/15
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=85166779207&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.108.045145
DO - 10.1103/PhysRevB.108.045145
M3 - Article
AN - SCOPUS:85166779207
SN - 2469-9950
VL - 108
JO - Physical Review B
JF - Physical Review B
IS - 4
M1 - 045145
ER -