Remanence Increase in SrFe<sub>12</sub>O<sub>19</sub>/Fe Exchange-Decoupled Hard-Soft Composite Magnets Owing to Dipolar Interactions
In the search for improved permanent magnets, fueled by the geostrategic and environmental issues associated with rare-earth-based magnets, magnetically hard (high anisotropy)-soft (high magnetization) composite magnets hold promise as alternative magnets that could replace modern permanent magnets,...
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| Format: | Article |
| Language: | English |
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MDPI AG
2023-07-01
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| Series: | Nanomaterials |
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| Online Access: | https://www.mdpi.com/2079-4991/13/14/2097 |
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| author | Jesús Carlos Guzmán-Mínguez Cecilia Granados-Miralles Patrick Kuntschke César de Julián Fernández Sergey Erokhin Dmitry Berkov Thomas Schliesch Jose Francisco Fernández Adrián Quesada |
| author_facet | Jesús Carlos Guzmán-Mínguez Cecilia Granados-Miralles Patrick Kuntschke César de Julián Fernández Sergey Erokhin Dmitry Berkov Thomas Schliesch Jose Francisco Fernández Adrián Quesada |
| author_sort | Jesús Carlos Guzmán-Mínguez |
| collection | DOAJ |
| description | In the search for improved permanent magnets, fueled by the geostrategic and environmental issues associated with rare-earth-based magnets, magnetically hard (high anisotropy)-soft (high magnetization) composite magnets hold promise as alternative magnets that could replace modern permanent magnets, such as rare-earth-based and ceramic magnets, in certain applications. However, so far, the magnetic properties reported for hard-soft composites have been underwhelming. Here, an attempt to further understand the correlation between magnetic and microstructural properties in strontium ferrite-based composites, hard SrFe<sub>12</sub>O<sub>19</sub> (SFO) ceramics with different contents of Fe particles as soft phase, both in powder and in dense injection molded magnets, is presented. In addition, the influence of soft phase particle dimension, in the nano- and micron-sized regimes, on these properties is studied. While Fe and SFO are not exchange-coupled in our magnets, a remanence that is higher than expected is measured. In fact, in composite injection molded anisotropic (magnetically oriented) magnets, remanence is improved by 2.4% with respect to a pure ferrite identical magnet. The analysis of the experimental results in combination with micromagnetic simulations allows us to establish that the type of interaction between hard and soft phases is of a dipolar nature, and is responsible for the alignment of a fraction of the soft spins with the magnetization of the hard. The mechanism unraveled in this work has implications for the development of novel hard-soft permanent magnets. |
| first_indexed | 2024-03-11T00:45:36Z |
| format | Article |
| id | doaj.art-0a18e36938f84bf38c0834ef7e9ba0ab |
| institution | Directory Open Access Journal |
| issn | 2079-4991 |
| language | English |
| last_indexed | 2024-03-11T00:45:36Z |
| publishDate | 2023-07-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Nanomaterials |
| spelling | doaj.art-0a18e36938f84bf38c0834ef7e9ba0ab2023-11-18T20:45:57ZengMDPI AGNanomaterials2079-49912023-07-011314209710.3390/nano13142097Remanence Increase in SrFe<sub>12</sub>O<sub>19</sub>/Fe Exchange-Decoupled Hard-Soft Composite Magnets Owing to Dipolar InteractionsJesús Carlos Guzmán-Mínguez0Cecilia Granados-Miralles1Patrick Kuntschke2César de Julián Fernández3Sergey Erokhin4Dmitry Berkov5Thomas Schliesch6Jose Francisco Fernández7Adrián Quesada8Electroceramic Department, Instituto de Cerámica y Vidrio, CSIC, 28049 Madrid, SpainElectroceramic Department, Instituto de Cerámica y Vidrio, CSIC, 28049 Madrid, SpainMax Baermann GmbH, 51429 Bergisch Gladbach, GermanyIstituto dei Materiali per l’Elettronica e il Magnetismo, CNR, 43124 Parma, ItalyGeneral Numerics Research Lab, 07743 Jena, GermanyGeneral Numerics Research Lab, 07743 Jena, GermanyMax Baermann GmbH, 51429 Bergisch Gladbach, GermanyElectroceramic Department, Instituto de Cerámica y Vidrio, CSIC, 28049 Madrid, SpainElectroceramic Department, Instituto de Cerámica y Vidrio, CSIC, 28049 Madrid, SpainIn the search for improved permanent magnets, fueled by the geostrategic and environmental issues associated with rare-earth-based magnets, magnetically hard (high anisotropy)-soft (high magnetization) composite magnets hold promise as alternative magnets that could replace modern permanent magnets, such as rare-earth-based and ceramic magnets, in certain applications. However, so far, the magnetic properties reported for hard-soft composites have been underwhelming. Here, an attempt to further understand the correlation between magnetic and microstructural properties in strontium ferrite-based composites, hard SrFe<sub>12</sub>O<sub>19</sub> (SFO) ceramics with different contents of Fe particles as soft phase, both in powder and in dense injection molded magnets, is presented. In addition, the influence of soft phase particle dimension, in the nano- and micron-sized regimes, on these properties is studied. While Fe and SFO are not exchange-coupled in our magnets, a remanence that is higher than expected is measured. In fact, in composite injection molded anisotropic (magnetically oriented) magnets, remanence is improved by 2.4% with respect to a pure ferrite identical magnet. The analysis of the experimental results in combination with micromagnetic simulations allows us to establish that the type of interaction between hard and soft phases is of a dipolar nature, and is responsible for the alignment of a fraction of the soft spins with the magnetization of the hard. The mechanism unraveled in this work has implications for the development of novel hard-soft permanent magnets.https://www.mdpi.com/2079-4991/13/14/2097hard-soft compositespermanent magnetsferritesdipolar interactions |
| spellingShingle | Jesús Carlos Guzmán-Mínguez Cecilia Granados-Miralles Patrick Kuntschke César de Julián Fernández Sergey Erokhin Dmitry Berkov Thomas Schliesch Jose Francisco Fernández Adrián Quesada Remanence Increase in SrFe<sub>12</sub>O<sub>19</sub>/Fe Exchange-Decoupled Hard-Soft Composite Magnets Owing to Dipolar Interactions Nanomaterials hard-soft composites permanent magnets ferrites dipolar interactions |
| title | Remanence Increase in SrFe<sub>12</sub>O<sub>19</sub>/Fe Exchange-Decoupled Hard-Soft Composite Magnets Owing to Dipolar Interactions |
| title_full | Remanence Increase in SrFe<sub>12</sub>O<sub>19</sub>/Fe Exchange-Decoupled Hard-Soft Composite Magnets Owing to Dipolar Interactions |
| title_fullStr | Remanence Increase in SrFe<sub>12</sub>O<sub>19</sub>/Fe Exchange-Decoupled Hard-Soft Composite Magnets Owing to Dipolar Interactions |
| title_full_unstemmed | Remanence Increase in SrFe<sub>12</sub>O<sub>19</sub>/Fe Exchange-Decoupled Hard-Soft Composite Magnets Owing to Dipolar Interactions |
| title_short | Remanence Increase in SrFe<sub>12</sub>O<sub>19</sub>/Fe Exchange-Decoupled Hard-Soft Composite Magnets Owing to Dipolar Interactions |
| title_sort | remanence increase in srfe sub 12 sub o sub 19 sub fe exchange decoupled hard soft composite magnets owing to dipolar interactions |
| topic | hard-soft composites permanent magnets ferrites dipolar interactions |
| url | https://www.mdpi.com/2079-4991/13/14/2097 |
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