Unit cell volume reduction of Gd5(Si,Ge)4 nanoparticles controlled by bulk compressibility

• Tipo: Artigo em Revista Científica Internacional
• Data: 2020

Autores

Andrade, VM (Autor) Outra; Belo, JH (Autor) Outra; Checca, NR (Autor) Outra; Rossi, A (Autor) Outra; Garcia, F (Autor) Outra; Almeida, B (Autor) Outra; Tedesco, JCG (Autor) Outra; Poulain, A (Autor) Outra; pereira, a. m. (Autor) FCUP; Reis, MS (Autor) Outra; araujo, j. p. (Autor) FCUP

Revista

Título: Journal of Alloys and Compounds

Vol. 849

ISSN: 0925-8388

Editora: Elsevier

Indexação

ISI Web of Knowledge - 4 Citações

Scopus - 2 Citações

Outras Informações

ID Authenticus: P-00S-MFD

DOI: 10.1016/j.jallcom.2020.156384

Abstract (EN): The production of Gd-5(Si,Ge)(4) compounds in reduced dimensionality, through pulsed laser deposition (PLD), have shown their potential for practical applications. Here, we present nanoparticles ranging from 10 to 27 nm of average particle size of Gd-5(SixGe1-x)(4), with x = 0, 0.45 and 0.60, obtained using an Nd:Yag (1064 nm) and an Excimer KrF laser (248 nm). Synchrotron X-ray Diffraction measurements revealed a reduced unit cell volume in comparison to their bulk counterpart. The x = 0 sample presented a similar to 1.99% reduction while x = 0.45 composition, a shrinkage of similar to 1.81% on the unit cell volume that are a result of a structural change to a Gd5Si4-type structure [O(I)]. In contrast, x = 0.60 nanoparticles conserve the bulk crystal structure with similar to 0.95% of volume shrinkage. As a consequence, there is a change on the magnetic transition order from a first to a second one for all nanostructures followed by a magnetocaloric response reduction. These observations unveil a direct correlation between the bulk compressibility values and the unit cell shrinkage, suggesting that the rise of a surface stress plays a major role on the particle and unit cell dimensions.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 9