Phase Competitions behind the Giant Magnetic Entropy Variation: Gd5Si2Ge2 and Tb5Si2Ge2 Case Studies
Ana Lúcia Pires,
João Horta Belo,
Armandina Maria Lima Lopes,
Isabel T. Gomes,
Luis Morellón,
Cesar Magen,
Pedro Antonio Algarabel,
Manuel Ricardo Ibarra,
André Miguel Pereira,
João Pedro Araújo
Affiliations
Ana Lúcia Pires
IFIMUP and IN—Institute of Nanoscience and Nanotechnology, Departamento de Física e Astronomia da Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, 687, Porto 4769-007, Portugal
João Horta Belo
IFIMUP and IN—Institute of Nanoscience and Nanotechnology, Departamento de Física e Astronomia da Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, 687, Porto 4769-007, Portugal
Armandina Maria Lima Lopes
IFIMUP and IN—Institute of Nanoscience and Nanotechnology, Departamento de Física e Astronomia da Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, 687, Porto 4769-007, Portugal
Isabel T. Gomes
IFIMUP and IN—Institute of Nanoscience and Nanotechnology, Departamento de Física e Astronomia da Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, 687, Porto 4769-007, Portugal
Luis Morellón
Instituto de Nanociencia de Aragón, Universidad de Zaragoza, ES-50018 Zaragoza, Spain and Departamento de Física de la Materia Condensada, Universidad de Zaragoza, Zaragoza 50009, Spain
Cesar Magen
Instituto de Nanociencia de Aragón, Universidad de Zaragoza, ES-50018 Zaragoza, Spain and Departamento de Física de la Materia Condensada, Universidad de Zaragoza, Zaragoza 50009, Spain
Pedro Antonio Algarabel
Instituto de Ciencia de Materiales de Aragón, CSIC-Universidad de Zaragoza, and Departamento de Física de la Materia Condensada, Universidad de Zaragoza, Zaragoza 50009, Spain
Manuel Ricardo Ibarra
Instituto de Nanociencia de Aragón, Universidad de Zaragoza, ES-50018 Zaragoza, Spain and Departamento de Física de la Materia Condensada, Universidad de Zaragoza, Zaragoza 50009, Spain
André Miguel Pereira
IFIMUP and IN—Institute of Nanoscience and Nanotechnology, Departamento de Física e Astronomia da Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, 687, Porto 4769-007, Portugal
João Pedro Araújo
IFIMUP and IN—Institute of Nanoscience and Nanotechnology, Departamento de Física e Astronomia da Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, 687, Porto 4769-007, Portugal
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.
