Phase Competitions behind the Giant Magnetic Entropy Variation: Gd5Si2Ge2 and Tb5Si2Ge2 Case Studies

Lúcia Pires, Ana ; Horta Belo, João ; Lima Lopes, Armandina Maria ; Gomes, Isabel T. ; Morellón, Luis (Universidad de Zaragoza) ; Magen, Cesar (Universidad de Zaragoza) ; Algarabel, Pedro Antonio ; Ibarra, Manuel Ricardo ; Pereira, André Miguel ; Araújo, João Pedro

Resumen: Magnetic materials with strong spin-lattice coupling are a powerful set of candidates for multifunctional applications because of their multiferroic, magnetocaloric (MCE), magnetostrictive and magnetoresistive effects. In these materials there is a strong competition between two states (where a state comprises an atomic and an associated magnetic structure) that leads to the occurrence of phase transitions under subtle variations of external parameters, such as temperature, magnetic field and hydrostatic pressure. In this review a general method combining detailed magnetic measurements/analysis and first principles calculations with the purpose of estimating the phase transition temperature is presented with the help of two examples (Gd5Si2Ge2 and Tb5Si2Ge2). It is demonstrated that such method is an important tool for a deeper understanding of the (de)coupled nature of each phase transition in the materials belonging to the R5(Si,Ge)4 family and most possibly can be applied to other systems. The exotic Griffiths-like phase in the framework of the R5(SixGe1-x)4 compounds is reviewed and its generalization as a requisite for strong phase competitions systems that present large magneto-responsive properties is proposed.

Idioma: Inglés

DOI: 10.3390/e16073813

Año: 2014

Publicado en: ENTROPY 16, 7 (2014), 3813-3831
ISSN: 1099-4300

Factor impacto JCR: 1.502 (2014)

Categ. JCR: PHYSICS, MULTIDISCIPLINARY rank: 34 / 78 = 0.436 (2014) - Q2 - T2

Tipo y forma: Article (Published version)

Área (Departamento): Física de la Materia Condensada (Departamento de Física de la Materia Condensada)