Structural and magnetic properties of Ho-5(SixGe1-x)(4)

• Tipo: Artigo em Revista Científica Internacional
• Data: 2008

Autores

pereira, a. m. (Autor) Outra; sousa, j. b. (Autor) FCUP; araujo, j. p. (Autor) FCUP; magen, c. (Autor) Outra; algarabel, p. a. (Autor) Outra; morellon, l. (Autor) Outra; marquina, c. (Autor) Outra; ibarra, m. r. (Autor) Outra

Revista

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Título: PHYSICAL REVIEW B

Vol. 77

ISSN: 2469-9950

Indexação

ISI Web of Knowledge - 18 Citações

Scopus - 22 Citações

Outras Informações

ID Authenticus: P-004-0PH

DOI: 10.1103/physrevb.77.134404

Abstract (EN): The crystal structure, phase relationship, and magnetic properties of the system Ho(5)(Si(x)Ge(1-x))(4) have been studied using polycrystalline samples with compositions x=0, 0.25, 0.5, 0.75, 0.875, and 1. At room temperature, the concentration range 0 <= x <= 0.5 presents an orthorhombic Sm(5)Ge(4)-type O(II) structure, whereas the monoclinic M phase sets in the compounds with concentrations x=0.75 and 0.875. The orthorhombic Gd(5)Si(4)-type O(I) structure is present only for x=1. Magnetic characterization has shown that the Ho(5)(Si(x)Ge(1-x))(4) system is paramagnetic at 300 K. The samples with an O(II) structure undergo a second order antiferromagnetic transition with T(N) between 25 and 30 K. The compounds with x > 0.5 present a low temperature ferromagnetic phase with T(C) rapidly increasing with Si content (dT(C)/dx=95 K). A second magnetic transition has been detected in the whole composition range at T(SR)similar to 15 K, which might correspond to a reorientation of the easy magnetization axis. Linear thermal expansion experiments evidence no spontaneous structural transition with the exception of Ho(5)Ge(4), where a small anomaly has been observed, which is probably due to the structural change of a small fraction of the sample volume.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 7