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Silva RS, Rodrigues JE, Gainza J, Serrano-Sánchez F, Martínez L, Huttel Y, Martínez JL, Alonso JA. Magnetoelastic Coupling Evidence by Anisotropic Crossed Thermal Expansion in Magnetocaloric RSrCoFeO 6 (R = Sm, Eu) Double Perovskites. Inorg Chem 2024; 63:7007-7018. [PMID: 38557070 PMCID: PMC11022179 DOI: 10.1021/acs.inorgchem.4c00594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 03/15/2024] [Accepted: 03/19/2024] [Indexed: 04/04/2024]
Abstract
Double perovskite oxides, characterized by their tunable magnetic properties and robust interconnection between the lattice and magnetic degrees of freedom, present an enticing foundation for advanced magnetic refrigeration materials. Herein, we delve into the influence of rare-earth elements on RSrCoFeO6 (R = Sm, Eu) disordered double perovskites by examining their structural, electronic, magnetic, and magnetocaloric properties. Temperature-dependent synchrotron X-ray diffraction analysis confirmed the stability of the orthorhombic phase (Pnma) across a wide temperature range. X-ray photoemission spectroscopy revealed that both Sm and Eu are in the 3+ state, whereas multiple states for Co2+/3+ and Fe3+/4+ are identified. The magnetic investigation and magnetocaloric effect (MCE) analysis brought to light the presence of a long-range antiferromagnetic (AFM) order with a second-order phase transition (SOPT) in both samples. The maximum magnetic entropy change ΔSMmax was approximately 0.9 J/kg K for both samples at applied field 0-7 T, manifesting prominently above Neel temperatures TN ≈ 93 K (Sm) and 84 K (Eu). Nevertheless, different relative cooling powers (RCP) of 112.6 J/kg (Sm) and 95.5 J/kg (Eu) were observed. A detailed analysis of the temperature-dependent lattice parameters shed light on a distinct magnetocaloric effect across the magnetic transition temperature, unveiling an anisotropic thermal expansion [αV = 1.41 × 10-5 K-1 (Sm) and αV = 1.54 × 10-5 K-1 (Eu)] wherein the thermal expansion axial ratio αbSm/αbEu = 0.61 became lower with increasing temperature, which suggests that the Eu sample experiences a greater thermal expansion in the b-axis direction. At the atomic bonding level, the evidence for magnetoelastic coupling around the magnetic transition temperatures TN was found through the anomalies along the average Co/Fe-O bond distance, formal valence, octahedral distortion, as well as an anisotropic lattice expansion.
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Affiliation(s)
- Romualdo S. Silva
- Instituto
de Ciencia de Materiales de Madrid (ICMM), CSIC, E-28049 Madrid, Spain
| | - João E. Rodrigues
- European
Synchrotron Radiation Facility (ESRF), 71 Avenue des Martyrs, 38000 Grenoble, France
- CELLS-ALBA
Synchrotron Light Source, Cerdanyola del Vallès, E-08290 Barcelona, Spain
| | - Javier Gainza
- Instituto
de Ciencia de Materiales de Madrid (ICMM), CSIC, E-28049 Madrid, Spain
| | | | - Lidia Martínez
- Instituto
de Ciencia de Materiales de Madrid (ICMM), CSIC, E-28049 Madrid, Spain
| | - Yves Huttel
- Instituto
de Ciencia de Materiales de Madrid (ICMM), CSIC, E-28049 Madrid, Spain
| | - José Luis Martínez
- Instituto
de Ciencia de Materiales de Madrid (ICMM), CSIC, E-28049 Madrid, Spain
| | - José Antonio Alonso
- Instituto
de Ciencia de Materiales de Madrid (ICMM), CSIC, E-28049 Madrid, Spain
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Usachov DY, Tarasov AV, Glazkova D, Mende M, Schulz S, Poelchen G, Fedorov AV, Vilkov OY, Bokai KA, Stolyarov VS, Kliemt K, Krellner C, Vyalikh DV. Insight into the Temperature-Dependent Canting of 4f Magnetic Moments from 4f Photoemission. J Phys Chem Lett 2023:5537-5545. [PMID: 37294735 DOI: 10.1021/acs.jpclett.3c01276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The orientation of the 4f moments offers an additional degree of freedom for engineering the spin-related properties in spintronic nanostructures of lanthanides. Yet, precise monitoring of the direction of magnetic moments remains a challenge. Here, on the example of the antiferromagnets HoRh2Si2 and DyRh2Si2, we investigate the temperature-dependent canting of the 4f moments near the surface. We demonstrate that this canting can be understood in the framework of crystal electric field theory and the exchange magnetic interaction. Using photoelectron spectroscopy, we disclose subtle but certain temperature-dependent changes in the line shape of the 4f multiplet. These changes are directly linked to the canting of the 4f moments, which is different for the individual lanthanide layers near the surface. Our results illustrate the opportunity to monitor the orientation of the 4f-moments with high precision, which is essential for development of novel lanthanide-based nanostructures, interfaces, supramolecular complexes, and single-molecule magnets for various applications.
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Affiliation(s)
- D Yu Usachov
- St. Petersburg State University, 7/9 Universitetskaya nab., St. Petersburg, 199034, Russia
- Moscow Institute of Physics and Technology, Institute Lane 9, Dolgoprudny, 141701, Russia
- National University of Science and Technology MISIS, Moscow, 119049, Russia
| | - A V Tarasov
- St. Petersburg State University, 7/9 Universitetskaya nab., St. Petersburg, 199034, Russia
- Moscow Institute of Physics and Technology, Institute Lane 9, Dolgoprudny, 141701, Russia
| | - D Glazkova
- St. Petersburg State University, 7/9 Universitetskaya nab., St. Petersburg, 199034, Russia
| | - M Mende
- Institut für Festkörper- und Materialphysik, Technische Universität Dresden, Dresden D-01062, Germany
| | - S Schulz
- Institut für Festkörper- und Materialphysik, Technische Universität Dresden, Dresden D-01062, Germany
| | - G Poelchen
- Institut für Festkörper- und Materialphysik, Technische Universität Dresden, Dresden D-01062, Germany
| | - A V Fedorov
- Helmholtz-Zentrum Berlin für Materialien und Energie, Berlin 12489, Germany
| | - O Yu Vilkov
- St. Petersburg State University, 7/9 Universitetskaya nab., St. Petersburg, 199034, Russia
| | - K A Bokai
- St. Petersburg State University, 7/9 Universitetskaya nab., St. Petersburg, 199034, Russia
| | - V S Stolyarov
- Moscow Institute of Physics and Technology, Institute Lane 9, Dolgoprudny, 141701, Russia
- National University of Science and Technology MISIS, Moscow, 119049, Russia
- Dukhov Research Institute of Automatics (VNIIA), Moscow, 127055, Russia
| | - K Kliemt
- Kristall- und Materiallabor, Physikalisches Institut, Goethe-Universität Frankfurt, Max-von-Laue Strasse 1, D-60438 Frankfurt am Main, Germany
| | - C Krellner
- Kristall- und Materiallabor, Physikalisches Institut, Goethe-Universität Frankfurt, Max-von-Laue Strasse 1, D-60438 Frankfurt am Main, Germany
| | - D V Vyalikh
- Donostia International Physics Center (DIPC), 20018 Donostia/San Sebastián, Basque Country, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao, 48013, Spain
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