Orthorhombic distortion drives orbital ordering in the antiferromagnetic 3$d$1 Mott insulator PrTiO3

Mandal, Prithwijit; Ojha, Shashank Kumar; Wang, Duo; Patel, Ranjan Kumar; Kumar, Siddharth; Maity, Jyotirmay; Zhang, Zhan; Zhou, Hua; Klewe, Christoph; Shafer, Padraic; Sanyal, Biplab; Middey, Srimanta

doi:10.1103/physrevb.108.045145

Title: Orthorhombic distortion drives orbital ordering in the antiferromagnetic 3$$d$$¹ Mott insulator PrTiO₃

Journal Article · Fri Jul 28 00:00:00 EDT 2023 · Physical Review. B

DOI:https://doi.org/10.1103/physrevb.108.045145· OSTI ID:2281853

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^[1]; Zhang, Zhan ^[3]; Zhou, Hua ^[3]; Klewe, Christoph ^[4]; Shafer, Padraic ^[4];

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Indian Inst. of Technology (IIT), Bangalore (India)
Uppsala Univ. (Sweden); Macao Polytechnic Univ. (China)
Argonne National Laboratory (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). Advanced Light Source (ALS)
Uppsala Univ. (Sweden)

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 $RE$TiO₃ ($RE$ = rare-earth) series has been puzzling since the celebrated Kugel-Khomskii model of spin-orbital superexchange predicts ferromagnetism in an orbitally degenerate $$d$$¹ 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 ($$D_{2h}$$) 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 $$D_{2h}$$ 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 $RE$TiO₃.

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Research Organization:: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). Advanced Light Source (ALS); Argonne National Laboratory (ANL), Argonne, IL (United States). Advanced Photon Source (APS)

Sponsoring Organization:: USDOE Office of Science (SC), Basic Energy Sciences (BES). Scientific User Facilities (SUF)

Grant/Contract Number:: AC02-05CH11231; AC02-06CH11357

OSTI ID:: 2281853

Journal Information:: Physical Review. B, Vol. 108, Issue 4; ISSN 2469-9950

Publisher:: American Physical Society (APS)Copyright Statement

Country of Publication:: United States

Language:: English

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Title: Orthorhombic distortion drives orbital ordering in the antiferromagnetic 3$$d$$1 Mott insulator PrTiO3

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Title: Orthorhombic distortion drives orbital ordering in the antiferromagnetic 3$$d$$¹ Mott insulator PrTiO₃