Quantifying the deleterious role of strong correlations in La1-xCaxMnO3 at the magnetocaloric transition

• Tipo: Artigo em Revista Científica Internacional
• Data: 2015

Autores

Turcaud, JA (Autor) Outra; pereira, a. m. (Autor) FCUP; Cohen, LF (Autor) Outra

Revista

Título: Physical Review B - Condensed Matter and Materials Physics

Vol. 91

ISSN: 1098-0121

Editora: American Physical Society

Indexação

ISI Web of Knowledge - 9 Citações

Scopus - 8 Citações

Outras Informações

ID Authenticus: P-00G-98N

DOI: 10.1103/physrevb.91.134410

Abstract (EN): Here we study orthorhombic La1-xCaxMnO3 (LCMO) where x = 0.2, 0.25, and 0.3 measuring the magnetization, the magneto-Seebeck, and magnetovolume contraction as a function of temperature and magnetic field to examine the influence of lattice, spin, and electronic degrees of freedom. Making the assumption that these contributions are independent of each other allows us to isolate the purely magnetic contribution to the total entropy change. This is compared directly with the value predicted from a mean-field plus Bean-Rodbell model. The model allows the first order character of the transition to be determined, as well as assigning numeric values to the number of magnetic ions that make up preformed magnetic clusters, and to the magnitude of the spread in T-C. We quantify how the clusters, the T-C spread values, and the electronic contribution, impact deleteriously on the available entropy change in fixed magnetic field, as the first order nature of the transition strengthens.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 8