Multi-step and anomalous reproducible behaviour of the electrical resistivity near the first-order magnetostructural transition of Gd-5(Si0.1Ge0.9)(4)

• Tipo: Artigo em Revista Científica Internacional
• Data: 2005

Autores

Sousa, João Bessa (Autor) FCUP; Pereira, André M. (Autor) FCUP; Correia, Francisco C. (Autor) Outra; Teixeira, José Miguel (Autor) FCUP; Araújo, João Pedro (Autor) FCUP; Pinto, Ryan P. (Autor) Outra; Braga, Melissa E. (Autor) Outra; Morellón, Luis (Autor) Outra; Algarabel, Pedro A. (Autor) Outra; Magén, César (Autor) Outra; Ibarra, Manuel Ricardo (Autor) Outra

Revista

Título: Journal of Physics Condensed Matter

Vol. 17

Páginas: 2461-2476

ISSN: 0953-8984

Editora: Institute of Physics Publishing

Indexação

ISI Web of Knowledge - 10 Citações

Scopus - 11 Citações

Outras Informações

ID Authenticus: P-000-3TM

DOI: 10.1088/0953-8984/17/15/017

Abstract (EN): Very detailed measurements of the electrical resistivity of Gd-5(Si0.1Ge0.9)(4) are here reported, with special emphasis on the vicinity of the first-order (magneto structural) martensitic transition which occurs at T-S similar to 87 K. The data cover more than fifty thermal cycles spanning the temperature ranges of 300-10 K (long cycles) and 105-10 K (short cycles). In the initial 10300 K cycles the martensitic transition takes place in three closely-spaced steps, with associated resistance (R) discontinuities and large thermal hysteresis. In a subsequent series of short cycles (10-105 K) a unique transition occurs, exhibiting a common and quite reproducible R(T) behaviour within a small temperature range (Delta T similar to 4 K) below T-S, either in heating or cooling runs. Remarkably, this 'local reproducibility' (within AT) remains in spite of the significant resistance changes which occur outside the A T-range under thermal cycling. In particular the residual resistance systematically increases under thermal cycling, but the corresponding effect is absent in the AT temperature range. This excludes microcracking as a dominant resistive mechanism in our results, pointing to an intrinsic character of the reproducible behaviour just below T-S. We also analyse the R(T) behaviour when changing from long to short thermal cycles, and the R(T) evolution towards a reversible final behaviour, after extended thermal cycling.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 16