Magnetic ordering and table-like magnetocaloric effect in the hydrogen liquefaction region for Tb2Co(Si,Ge)
The investigation and understanding of the magnetic complexity in magnetic refrigeration candidates is crucial for a better search of new materials. This work investigates the magnetic ordering and magnetocaloric properties of Sc2CoSi2-type Tb2CoGe2 and Tb2CoSi2 intermetallic compounds. Through deta...
| Autores: | , , , , , , |
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| Formato: | artículo |
| Fecha de publicación: | 2026 |
| País: | España |
| Recursos: | Universidad del País Vasco |
| Repositorio: | Addi. Archivo Digital para la Docencia y la Investigación |
| OAI Identifier: | oai:dnet:addi________::677e7ebd1e894c21f7f0033a3b2f7eec |
| Acesso em linha: | http://hdl.handle.net/10810/79425 |
| Access Level: | acceso abierto |
| Palavra-chave: | magnetocaloric effect gas liquefaction neutron diffraction intermetallics |
| Resumo: | The investigation and understanding of the magnetic complexity in magnetic refrigeration candidates is crucial for a better search of new materials. This work investigates the magnetic ordering and magnetocaloric properties of Sc2CoSi2-type Tb2CoGe2 and Tb2CoSi2 intermetallic compounds. Through detailed magnetic measurements and neutron diffraction analysis, the study clarifies the impact of Si−Ge substitution on microscopic magnetic structures and macroscopic magnetocaloric performance. The substitution of Si by Ge leads to an expansion of the unit cell and strongly alters the magnetic behaviour. Tb2CoSi2 shows a high temperature paramagnetic (PM) to ferromagnetic (FM) transition at TC=198 K, a lower temperature spin reorientation transition at T_m= 75 K and an antiferromagnetic (AFM) transition at T_N= 13 K. In contrast, Tb2CoGe2 undergoes a PM to AFM transition at a significantly lower temperature, TN=126 K, before evolving into an FM-like state at TM=66 K. Neutron diffraction confirms that Tb2CoSi2 is an ac-plane collinear ferromagnet below TC, while Tb2CoGe2 is an ac-plane collinear antiferromagnet below TN. Tb2CoGe2 exhibits a metamagnetic transition from the antiferromagnetic state to a mixed collinear FM+AFM state upon application of an external magnetic field. Both compounds display a highly desirable table-like magnetocaloric effect over a wide temperature range, suitable for magnetic refrigeration applications in the N2 and H2 gas liquefaction regions. These findings emphasize that Si−Ge substitution is an effective mechanism for tuning magnetic properties in this intermetallic family in order to optimize their performance for magnetic refrigeration. |
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