Influence of Chemical Substitution and Light Element Insertion on the Magnetic Properties of Nanocrystalline Pr<sub>2</sub>Co<sub>7</sub> Compound
It is well recognized that intermetallics based on rare-earth (R) and transition metals (T) display numerous interesting magnetic properties, leading to potential applications in different fields. The latest progress regarding magnetic properties and the magnetocaloric effect (MCE) in the nanostruct...
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-01-01
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| Series: | Magnetochemistry |
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| Online Access: | https://www.mdpi.com/2312-7481/8/2/20 |
| _version_ | 1827654149966135296 |
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| author | Riadh Fersi Najeh Mliki Lotfi Bessais |
| author_facet | Riadh Fersi Najeh Mliki Lotfi Bessais |
| author_sort | Riadh Fersi |
| collection | DOAJ |
| description | It is well recognized that intermetallics based on rare-earth (R) and transition metals (T) display numerous interesting magnetic properties, leading to potential applications in different fields. The latest progress regarding magnetic properties and the magnetocaloric effect (MCE) in the nanostructured Pr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Co<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>7</mn></msub></semantics></math></inline-formula> compound, as well as its carbides and hydrides, is reviewed in this paper. Some of this progress reveals remarkable MCE performance, which makes it attractive in the field of magnetic refrigeration at high temperatures. With the purpose of understanding the magnetic and magnetocaloric characteristics of these compounds, the crystal structure, microstructure, and magnetism are also brought into focus. The Pr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Co<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>7</mn></msub></semantics></math></inline-formula> compound has interesting magnetic properties, such as a high Curie temperature T<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>C</mi></msub></semantics></math></inline-formula> and uniaxial magnetocrystalline anisotropy. It crystallizes in a hexagonal structure (2:7 H) of the Ce<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Ni<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>7</mn></msub></semantics></math></inline-formula> type and is stable at relatively low temperatures (T<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>a</mi></msub></semantics></math></inline-formula> ≤ 1023 K), or it has a rhombohedral structure (2:7 R) of the Gd<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Co<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>7</mn></msub></semantics></math></inline-formula> type and is stable at high temperatures (T<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>a</mi></msub></semantics></math></inline-formula> ≥ 1223 K). Studies of the magnetocaloric properties of the nanocrystalline Pr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Co<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>7</mn></msub></semantics></math></inline-formula> compound have shown the existence of a large reversible magnetic entropy change (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mo>Δ</mo></semantics></math></inline-formula>S<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>M</mi></msub></semantics></math></inline-formula>) with a second-order magnetic transition. After its substitution, we showed that nanocrystalline Pr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Co<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mrow><mn>7</mn><mo>−</mo><mi>x</mi></mrow></msub></semantics></math></inline-formula>Fe<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>x</mi></msub></semantics></math></inline-formula> compounds that were annealed at T<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>a</mi></msub></semantics></math></inline-formula> = 973 K crystallized in the 2:7 H structure similarly to the parent compound. The extended X-ray absorption fine-structure (EXAFS) spectra adjustments showed that Fe atoms preferably occupy the 12k site for x ≤ 1. The study of the magnetic properties of nanocrystalline Pr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Co<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mrow><mn>7</mn><mo>−</mo><mi>x</mi></mrow></msub></semantics></math></inline-formula>Fe<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>x</mi></msub></semantics></math></inline-formula> compounds revealed an increase in T<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>C</mi></msub></semantics></math></inline-formula> of about 26% for x = 0.5, as well as an improvement in the coercivity, H<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>c</mi></msub></semantics></math></inline-formula> (12 kOe), and the (BH)<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>max</mi></msub></semantics></math></inline-formula> (9 MGOe) product. On the other hand, the insertion of C atoms into the Pr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Co<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>7</mn></msub></semantics></math></inline-formula> cell led to a marked improvement in the T<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>C</mi></msub></semantics></math></inline-formula> value of 21.6%. The best magnetic properties were found for the Pr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Co<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>7</mn></msub></semantics></math></inline-formula>C<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mrow><mn>0.25</mn></mrow></msub></semantics></math></inline-formula> compound annealed at 973 K, H<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>c</mi></msub></semantics></math></inline-formula> = 10.3 kOe, and (BH)<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>max</mi></msub></semantics></math></inline-formula> = 11.5 MGOe. We studied the microstructure, hydrogenation, and magnetic properties of nanocrystalline Pr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Co<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>7</mn></msub></semantics></math></inline-formula>H<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>x</mi></msub></semantics></math></inline-formula> hydrides. The crystal structure of the Pr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Co<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>7</mn></msub></semantics></math></inline-formula> compound transformed from a hexagonal (P6<sub>3</sub>/mmc) into an orthorhombic (Pbcn) and monoclinic (C2/c) structure during hydrogenation. The absorption of H by the Pr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Co<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>7</mn></msub></semantics></math></inline-formula> compound led to an increase in the T<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>C</mi></msub></semantics></math></inline-formula> value from 600 K at x = 0 to 691 K at x = 3.75. The Pr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Co<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>7</mn></msub></semantics></math></inline-formula>H<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mrow><mn>0.25</mn></mrow></msub></semantics></math></inline-formula> hydride had optimal magnetic properties: H<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>c</mi></msub></semantics></math></inline-formula> = 6.1 KOe, (BH)<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>max</mi></msub></semantics></math></inline-formula> = 5.8 MGOe, and T<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>C</mi></msub></semantics></math></inline-formula> = 607 K. We tailored the mean field theory (MFT) and random magnetic anisotropy (RMA) methods to investigate the magnetic moments, exchange interactions, and magnetic anisotropy properties. The relationship between the microstructure and magnetic properties is discussed. The obtained results provide a fundamental reference for adapting the magnetic properties of the Pr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Co<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>7</mn></msub></semantics></math></inline-formula>, Pr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Co<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mrow><mn>6.5</mn></mrow></msub></semantics></math></inline-formula>Fe<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mrow><mn>0.5</mn></mrow></msub></semantics></math></inline-formula>, Pr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Co<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>7</mn></msub></semantics></math></inline-formula>C<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mrow><mn>0.25</mn></mrow></msub></semantics></math></inline-formula>, and Pr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Co<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>7</mn></msub></semantics></math></inline-formula>H<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mrow><mn>0.25</mn></mrow></msub></semantics></math></inline-formula> compounds for potential permanent nanomagnets, high-density magnetic recording, and magnetic refrigeration applications. |
| first_indexed | 2024-03-09T21:33:18Z |
| format | Article |
| id | doaj.art-57206a4328ee4dfba844751e68dd6f0c |
| institution | Directory Open Access Journal |
| issn | 2312-7481 |
| language | English |
| last_indexed | 2024-03-09T21:33:18Z |
| publishDate | 2022-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Magnetochemistry |
| spelling | doaj.art-57206a4328ee4dfba844751e68dd6f0c2023-11-23T20:49:20ZengMDPI AGMagnetochemistry2312-74812022-01-01822010.3390/magnetochemistry8020020Influence of Chemical Substitution and Light Element Insertion on the Magnetic Properties of Nanocrystalline Pr<sub>2</sub>Co<sub>7</sub> CompoundRiadh Fersi0Najeh Mliki1Lotfi Bessais2Department of Physics, University Paris Est Creteil, CNRS, ICMPE, 2 Rue Henri Dunant, F-94320 Thiais, FranceLaboratory of Materials Organization and Properties, Faculty of Science of Tunis, University of Tunis El Manar, Tunis 2092, TunisiaDepartment of Physics, University Paris Est Creteil, CNRS, ICMPE, 2 Rue Henri Dunant, F-94320 Thiais, FranceIt is well recognized that intermetallics based on rare-earth (R) and transition metals (T) display numerous interesting magnetic properties, leading to potential applications in different fields. The latest progress regarding magnetic properties and the magnetocaloric effect (MCE) in the nanostructured Pr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Co<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>7</mn></msub></semantics></math></inline-formula> compound, as well as its carbides and hydrides, is reviewed in this paper. Some of this progress reveals remarkable MCE performance, which makes it attractive in the field of magnetic refrigeration at high temperatures. With the purpose of understanding the magnetic and magnetocaloric characteristics of these compounds, the crystal structure, microstructure, and magnetism are also brought into focus. The Pr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Co<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>7</mn></msub></semantics></math></inline-formula> compound has interesting magnetic properties, such as a high Curie temperature T<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>C</mi></msub></semantics></math></inline-formula> and uniaxial magnetocrystalline anisotropy. It crystallizes in a hexagonal structure (2:7 H) of the Ce<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Ni<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>7</mn></msub></semantics></math></inline-formula> type and is stable at relatively low temperatures (T<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>a</mi></msub></semantics></math></inline-formula> ≤ 1023 K), or it has a rhombohedral structure (2:7 R) of the Gd<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Co<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>7</mn></msub></semantics></math></inline-formula> type and is stable at high temperatures (T<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>a</mi></msub></semantics></math></inline-formula> ≥ 1223 K). Studies of the magnetocaloric properties of the nanocrystalline Pr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Co<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>7</mn></msub></semantics></math></inline-formula> compound have shown the existence of a large reversible magnetic entropy change (<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mo>Δ</mo></semantics></math></inline-formula>S<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>M</mi></msub></semantics></math></inline-formula>) with a second-order magnetic transition. After its substitution, we showed that nanocrystalline Pr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Co<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mrow><mn>7</mn><mo>−</mo><mi>x</mi></mrow></msub></semantics></math></inline-formula>Fe<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>x</mi></msub></semantics></math></inline-formula> compounds that were annealed at T<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>a</mi></msub></semantics></math></inline-formula> = 973 K crystallized in the 2:7 H structure similarly to the parent compound. The extended X-ray absorption fine-structure (EXAFS) spectra adjustments showed that Fe atoms preferably occupy the 12k site for x ≤ 1. The study of the magnetic properties of nanocrystalline Pr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Co<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mrow><mn>7</mn><mo>−</mo><mi>x</mi></mrow></msub></semantics></math></inline-formula>Fe<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>x</mi></msub></semantics></math></inline-formula> compounds revealed an increase in T<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>C</mi></msub></semantics></math></inline-formula> of about 26% for x = 0.5, as well as an improvement in the coercivity, H<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>c</mi></msub></semantics></math></inline-formula> (12 kOe), and the (BH)<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>max</mi></msub></semantics></math></inline-formula> (9 MGOe) product. On the other hand, the insertion of C atoms into the Pr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Co<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>7</mn></msub></semantics></math></inline-formula> cell led to a marked improvement in the T<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>C</mi></msub></semantics></math></inline-formula> value of 21.6%. The best magnetic properties were found for the Pr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Co<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>7</mn></msub></semantics></math></inline-formula>C<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mrow><mn>0.25</mn></mrow></msub></semantics></math></inline-formula> compound annealed at 973 K, H<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>c</mi></msub></semantics></math></inline-formula> = 10.3 kOe, and (BH)<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>max</mi></msub></semantics></math></inline-formula> = 11.5 MGOe. We studied the microstructure, hydrogenation, and magnetic properties of nanocrystalline Pr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Co<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>7</mn></msub></semantics></math></inline-formula>H<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>x</mi></msub></semantics></math></inline-formula> hydrides. The crystal structure of the Pr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Co<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>7</mn></msub></semantics></math></inline-formula> compound transformed from a hexagonal (P6<sub>3</sub>/mmc) into an orthorhombic (Pbcn) and monoclinic (C2/c) structure during hydrogenation. The absorption of H by the Pr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Co<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>7</mn></msub></semantics></math></inline-formula> compound led to an increase in the T<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>C</mi></msub></semantics></math></inline-formula> value from 600 K at x = 0 to 691 K at x = 3.75. The Pr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Co<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>7</mn></msub></semantics></math></inline-formula>H<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mrow><mn>0.25</mn></mrow></msub></semantics></math></inline-formula> hydride had optimal magnetic properties: H<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>c</mi></msub></semantics></math></inline-formula> = 6.1 KOe, (BH)<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>max</mi></msub></semantics></math></inline-formula> = 5.8 MGOe, and T<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mi>C</mi></msub></semantics></math></inline-formula> = 607 K. We tailored the mean field theory (MFT) and random magnetic anisotropy (RMA) methods to investigate the magnetic moments, exchange interactions, and magnetic anisotropy properties. The relationship between the microstructure and magnetic properties is discussed. The obtained results provide a fundamental reference for adapting the magnetic properties of the Pr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Co<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>7</mn></msub></semantics></math></inline-formula>, Pr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Co<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mrow><mn>6.5</mn></mrow></msub></semantics></math></inline-formula>Fe<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mrow><mn>0.5</mn></mrow></msub></semantics></math></inline-formula>, Pr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Co<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>7</mn></msub></semantics></math></inline-formula>C<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mrow><mn>0.25</mn></mrow></msub></semantics></math></inline-formula>, and Pr<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>2</mn></msub></semantics></math></inline-formula>Co<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mn>7</mn></msub></semantics></math></inline-formula>H<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msub><mrow></mrow><mrow><mn>0.25</mn></mrow></msub></semantics></math></inline-formula> compounds for potential permanent nanomagnets, high-density magnetic recording, and magnetic refrigeration applications.https://www.mdpi.com/2312-7481/8/2/20intermetallicsnanomaterialsmicrostructural propertiesmagnetic propertiesmagnetocaloric properties |
| spellingShingle | Riadh Fersi Najeh Mliki Lotfi Bessais Influence of Chemical Substitution and Light Element Insertion on the Magnetic Properties of Nanocrystalline Pr<sub>2</sub>Co<sub>7</sub> Compound Magnetochemistry intermetallics nanomaterials microstructural properties magnetic properties magnetocaloric properties |
| title | Influence of Chemical Substitution and Light Element Insertion on the Magnetic Properties of Nanocrystalline Pr<sub>2</sub>Co<sub>7</sub> Compound |
| title_full | Influence of Chemical Substitution and Light Element Insertion on the Magnetic Properties of Nanocrystalline Pr<sub>2</sub>Co<sub>7</sub> Compound |
| title_fullStr | Influence of Chemical Substitution and Light Element Insertion on the Magnetic Properties of Nanocrystalline Pr<sub>2</sub>Co<sub>7</sub> Compound |
| title_full_unstemmed | Influence of Chemical Substitution and Light Element Insertion on the Magnetic Properties of Nanocrystalline Pr<sub>2</sub>Co<sub>7</sub> Compound |
| title_short | Influence of Chemical Substitution and Light Element Insertion on the Magnetic Properties of Nanocrystalline Pr<sub>2</sub>Co<sub>7</sub> Compound |
| title_sort | influence of chemical substitution and light element insertion on the magnetic properties of nanocrystalline pr sub 2 sub co sub 7 sub compound |
| topic | intermetallics nanomaterials microstructural properties magnetic properties magnetocaloric properties |
| url | https://www.mdpi.com/2312-7481/8/2/20 |
| work_keys_str_mv | AT riadhfersi influenceofchemicalsubstitutionandlightelementinsertiononthemagneticpropertiesofnanocrystallineprsub2subcosub7subcompound AT najehmliki influenceofchemicalsubstitutionandlightelementinsertiononthemagneticpropertiesofnanocrystallineprsub2subcosub7subcompound AT lotfibessais influenceofchemicalsubstitutionandlightelementinsertiononthemagneticpropertiesofnanocrystallineprsub2subcosub7subcompound |