Magneto-optical evidence of double exchange in a percolating lattice

• Tipo: Artigo em Revista Científica Internacional
• Data: 2006

Autores

Caimi, G (Autor) Outra; Perucchi, A (Autor) Outra; Degiorgi, L (Autor) Outra; Ott, HR (Autor) Outra; Pereira, VM (Autor) FCUP; Castro Neto, AH (Autor) Outra; Bianchi, AD (Autor) Outra; Fisk, Z (Autor) Outra

Revista

Título: Physical Review Letters

Vol. 96

ISSN: 0031-9007

Editora: American Physical Society

Indexação

ISI Web of Knowledge - 18 Citações

Scopus - 17 Citações

Outras Informações

ID Authenticus: P-004-NPK

DOI: 10.1103/physrevlett.96.016403

Abstract (EN): Substituting Eu by Ca in ferromagnetic EuB6 leads to a percolation limited magnetic ordering. We present and discuss magneto-optical data of the Eu1-xCaxB6 series, based on measurements of the reflectivity R(omega) from the far infrared up to the ultraviolet, as a function of temperature and magnetic field. Via the Kramers-Kronig transformation of R(omega) we extract the complete absorption spectra of samples with different values of x. The change of the spectral weight in the Drude component by increasing the magnetic field agrees with a scenario based on the double-exchange model, and suggests a crossover from a ferromagnetic metal to a ferromagnetic Anderson insulator upon increasing Ca content at low temperatures.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 4