Journal Club do Departamento de Física dos Materiais e Mecânica – FMT
Nesta semana o pós-graduando Gerson de Carli Proença de Almeida Pessotto, do Laboratório de Materiais Magnéticos, apresentará o artigo: “Non-hysteretic first-order phase transition with large latent heat and giant low-field magnetocaloric effect”, F. Guillou et al.
Dia: 26 de setembro, quarta-feira, às 12h10
Local: Sala de Seminários José Roberto Leite Edifício Alessandro Volta (bloco C).
Abstract:
First-order magnetic transitions (FOMTs) with a large discontinuity in magnetization are highly sought in the development of advanced functional magnetic materials. Isosymmetric magnetoelastic FOMTs that do not perturb crystal symmetry are especially rare, and only a handful of material families, almost exclusively transition metalbased, are known to exhibit them. Yet, here we report a surprising isosymmetric FOMT in a rare-earth intermetallic, Eu2In. What makes this transition in Eu2In even more remarkable is that it is associated with a large latent heat and an exceptionally high magnetocaloric effect in low magnetic fields, but with tiny lattice discontinuities and negligible hysteresis. An active role of the Eu-5d and In4p states and a rather unique electronic structure borne by In to Eu charge transfer, altogether result in an unusual exchange mechanism that both sets the transition in motion and unveils an approach toward developing specific magnetic functionalities ad libitum.
Nature Communication DOI: 10.1038/s41467-018-05268-4
