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Fuentes V, Balcells L, Konstantinović Z, Martínez B, Pomar A. Evaluation of Sputtering Processes in Strontium Iridate Thin Films. NANOMATERIALS (BASEL, SWITZERLAND) 2024; 14:242. [PMID: 38334512 PMCID: PMC10856326 DOI: 10.3390/nano14030242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2023] [Revised: 01/19/2024] [Accepted: 01/20/2024] [Indexed: 02/10/2024]
Abstract
The growth of epitaxial thin films from the Ruddlesden-Popper series of strontium iridates by magnetron sputtering is analyzed. It was found that, even using a non-stoichiometric target, the films formed under various conditions were consistently of the perovskite-like n = ∞ SrIrO3 phase, with no evidence of other RP series phases. A detailed inspection of the temperature-oxygen phase diagram underscored that kinetics mechanisms prevail over thermodynamics considerations. The analysis of the angular distribution of sputtered iridium and strontium species indicated clearly different spatial distribution patterns. Additionally, significant backsputtering was detected at elevated temperatures. Thus, it is assumed that the interplay between these two kinetic phenomena is at the origin of the preferential nucleation of the SrIrO3 phase. In addition, strategies for controlling cation stoichiometry off-axis have also been explored. Finally, the long-term stability of the films has been demonstrated.
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Affiliation(s)
- Víctor Fuentes
- Instituto de Ciencia de Materiales de Barcelona, ICMAB-CSIC, Campus Universitario UAB, 08193 Bellaterra, Spain; (V.F.); (L.B.); (B.M.)
| | - Lluis Balcells
- Instituto de Ciencia de Materiales de Barcelona, ICMAB-CSIC, Campus Universitario UAB, 08193 Bellaterra, Spain; (V.F.); (L.B.); (B.M.)
| | - Zorica Konstantinović
- Center for Solid State Physics and New Materials, Institute of Physics Belgrade, University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia
| | - Benjamín Martínez
- Instituto de Ciencia de Materiales de Barcelona, ICMAB-CSIC, Campus Universitario UAB, 08193 Bellaterra, Spain; (V.F.); (L.B.); (B.M.)
| | - Alberto Pomar
- Instituto de Ciencia de Materiales de Barcelona, ICMAB-CSIC, Campus Universitario UAB, 08193 Bellaterra, Spain; (V.F.); (L.B.); (B.M.)
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2
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Yao Y, Willa R, Lacmann T, Souliou SM, Frachet M, Willa K, Merz M, Weber F, Meingast C, Heid R, Haghighirad AA, Schmalian J, Le Tacon M. An electronic nematic liquid in BaNi 2As 2. Nat Commun 2022; 13:4535. [PMID: 35927267 PMCID: PMC9352674 DOI: 10.1038/s41467-022-32112-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Accepted: 07/14/2022] [Indexed: 11/25/2022] Open
Abstract
Understanding the organizing principles of interacting electrons and the emergence of novel electronic phases is a central endeavor of condensed matter physics. Electronic nematicity, in which the discrete rotational symmetry in the electron fluid is broken while the translational one remains unaffected, is a prominent example of such a phase. It has proven ubiquitous in correlated electron systems, and is of prime importance to understand Fe-based superconductors. Here, we find that fluctuations of such broken symmetry are exceptionally strong over an extended temperature range above phase transitions in \documentclass[12pt]{minimal}
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\begin{document}$${{{{{\rm{Ba}}}}}}{{{{{{\rm{Ni}}}}}}}_{2}{({{{{{{\rm{As}}}}}}}_{1-x}{{{{{{\rm{P}}}}}}}_{x})}_{2}$$\end{document}BaNi2(As1−xPx)2, the nickel homologue to the Fe-based systems. This lends support to a type of electronic nematicity, dynamical in nature, which exhibits a particularly strong coupling to the underlying crystal lattice. Fluctuations between degenerate nematic configurations cause splitting of phonon lines, without lifting degeneracies nor breaking symmetries, akin to spin liquids in magnetic systems. Electronic nematicity is typically associated with the breaking of rotational symmetry. Here the authors report unusual nematicity in BaNi2As2, manifested in a large splitting of the optical phonon mode above the structural transition temperature, and link it to the coupling between the lattice and nematic fluctuations.
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Affiliation(s)
- Yi Yao
- Institut für Quantenmaterialien und -technologien, Karlsruher Institut für Technologie, 76021, Karlsruhe, Germany
| | - Roland Willa
- Institut für Theorie der Kondensierten Materie, Karlsruher Institut für Technologie, 76131, Karlsruhe, Germany
| | - Tom Lacmann
- Institut für Quantenmaterialien und -technologien, Karlsruher Institut für Technologie, 76021, Karlsruhe, Germany
| | - Sofia-Michaela Souliou
- Institut für Quantenmaterialien und -technologien, Karlsruher Institut für Technologie, 76021, Karlsruhe, Germany
| | - Mehdi Frachet
- Institut für Quantenmaterialien und -technologien, Karlsruher Institut für Technologie, 76021, Karlsruhe, Germany
| | - Kristin Willa
- Institut für Quantenmaterialien und -technologien, Karlsruher Institut für Technologie, 76021, Karlsruhe, Germany
| | - Michael Merz
- Institut für Quantenmaterialien und -technologien, Karlsruher Institut für Technologie, 76021, Karlsruhe, Germany.,Karlsruhe Nano Micro Facility (KNMFi), Karlsruhe Institute of Technology (KIT), 76344, Eggenstein-Leopoldshafen, Germany
| | - Frank Weber
- Institut für Quantenmaterialien und -technologien, Karlsruher Institut für Technologie, 76021, Karlsruhe, Germany
| | - Christoph Meingast
- Institut für Quantenmaterialien und -technologien, Karlsruher Institut für Technologie, 76021, Karlsruhe, Germany
| | - Rolf Heid
- Institut für Quantenmaterialien und -technologien, Karlsruher Institut für Technologie, 76021, Karlsruhe, Germany
| | - Amir-Abbas Haghighirad
- Institut für Quantenmaterialien und -technologien, Karlsruher Institut für Technologie, 76021, Karlsruhe, Germany
| | - Jörg Schmalian
- Institut für Quantenmaterialien und -technologien, Karlsruher Institut für Technologie, 76021, Karlsruhe, Germany.,Institut für Theorie der Kondensierten Materie, Karlsruher Institut für Technologie, 76131, Karlsruhe, Germany
| | - Matthieu Le Tacon
- Institut für Quantenmaterialien und -technologien, Karlsruher Institut für Technologie, 76021, Karlsruhe, Germany.
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Kloß SD, Weidemann ML, Attfield JP. Preparation of Bulk‐Phase Nitride Perovskite LaReN
3
and Topotactic Reduction to LaNiO
2
‐Type LaReN
2. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202108759] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Simon D. Kloß
- Centre for Science at Extreme Conditions University of Edinburgh Edinburgh EH9 3FD UK
- Ludwig-Maximilians-University Munich Department Chemistry 81377 Munich Germany
| | - Martin L. Weidemann
- Ludwig-Maximilians-University Munich Department Chemistry 81377 Munich Germany
| | - J. Paul Attfield
- Centre for Science at Extreme Conditions University of Edinburgh Edinburgh EH9 3FD UK
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Kloß SD, Weidemann ML, Attfield JP. Preparation of Bulk-Phase Nitride Perovskite LaReN 3 and Topotactic Reduction to LaNiO 2 -Type LaReN 2. Angew Chem Int Ed Engl 2021; 60:22260-22264. [PMID: 34355842 DOI: 10.1002/anie.202108759] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 08/02/2021] [Indexed: 11/09/2022]
Abstract
While halide and oxide perovskites are numerous and many display outstanding properties, ABN3 perovskite nitrides are extremely rare due to synthetic challenges arising from the low chemical potential of nitrogen and a tendency to form low-coordination nitridometallate anions. We report the preparation of a perovskite nitride LaReN3 through azide-mediated oxidation at high pressure. High-resolution synchrotron diffraction shows that LaReN3 has a low-symmetry, triclinic, perovskite superstructure resulting from orbital ordering with strong spin-orbit coupling distortions. Topotactic reduction of LaReN3 above 500 °C leads to layered tetragonal LaReN2 via a probable LaReN2.5 intermediate, which is the first reported example of nitride defect perovskites. Magnetisation and conductivity measurements indicate that LaReN3 and LaReN2 are both metallic solids. The two chemical approaches presented are expected to lead to new classes of ABN3 and defect ABN3-x nitride perovskite materials.
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Affiliation(s)
- Simon D Kloß
- Centre for Science at Extreme Conditions, University of Edinburgh, Edinburgh, EH9 3FD, UK.,Ludwig-Maximilians-University Munich, Department Chemistry, 81377, Munich, Germany
| | - Martin L Weidemann
- Ludwig-Maximilians-University Munich, Department Chemistry, 81377, Munich, Germany
| | - J Paul Attfield
- Centre for Science at Extreme Conditions, University of Edinburgh, Edinburgh, EH9 3FD, UK
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Bhowal S, Dasgupta I. Spin-orbit effects in pentavalent iridates: models and materials. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2021; 33:453001. [PMID: 34352745 DOI: 10.1088/1361-648x/ac1aed] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 08/05/2021] [Indexed: 06/13/2023]
Abstract
Spin-orbit effects in heavy 5dtransition metal oxides, in particular, iridates, have received enormous current interest due to the prediction as well as the realization of a plethora of exotic and unconventional magnetic properties. While a bulk of these works are based on tetravalent iridates (d5), where the counter-intuitive insulating state of the rather extended 5dorbitals are explained by invoking strong spin-orbit coupling, the recent quest in iridate research has shifted to the other valencies of Ir, of which pentavalent iridates constitute a notable representative. In contrast to the tetravalent iridates, spin-orbit entangled electrons ind4systems are expected to be confined to theJ= 0 singlet state without any resultant moment or magnetic response. However, it has been recently predicted that, magnetism ind4systems may occur via magnetic condensation of excitations across spin-orbit-coupled states. In reality, the magnetism in Ir5+systems are often quite debatable both from theoretical as well as experimental point of view. Here we provide a comprehensive overview of the spin-orbit coupledd4model systems and its implications in the studied pentavalent iridates. In particular, we review here the current experimental and theoretical understanding of the double perovskite (A2BYIrO6,A= Sr, Ba,B= Y, Sc, Gd), 6H-perovskite (Ba3MIr2O9,M= Zn, Mg, Sr, Ca), post-perovskite (NaIrO3), and hexagonal (Sr3MIrO6) iridates, along with a number of open questions that require future investigation.
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Affiliation(s)
- Sayantika Bhowal
- School of Physical Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032, India
| | - Indra Dasgupta
- School of Physical Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032, India
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