Repositório Digital

A- A A+

B3LYP density functional calculations on the ground-state structure, elastic properties, and compression mechanism of α-ZrW/sub 2/O/sub 8/

.

B3LYP density functional calculations on the ground-state structure, elastic properties, and compression mechanism of α-ZrW/sub 2/O/sub 8/

Mostrar registro completo

Estatísticas

Título B3LYP density functional calculations on the ground-state structure, elastic properties, and compression mechanism of α-ZrW/sub 2/O/sub 8/
Autor Figueiredo, Camila Araújo de
Perottoni, Claudio Antonio
Abstract The structure of -ZrW2O8 was optimized at different pressures and its elastic constants were calculated at the B3LYP density functional level of theory. Overall, the relative stiffnesses of the atomic bonds and linkages, ranked in terms of bond compressibilities, decrease according to the sequence W-O Zr...W Zr-O. The tetrahedra around tungsten atoms are found to be much stiffer than the α-ZrO6 octahedra. These latter are, in fact, more compressible than the α-ZrW2O8 unit cell. The elastic constants calculated in the athermal limit are in excellent agreement with recent experimental results obtained near 0 K. The α-ZrW2O8 compression mechanism around W1 and W2 atoms is quite different. While the former can be described essentially in terms of a correlated polyhedral rotation, the latter involves correlated rotation of the first coordination polyhedra and translation of WO4 units downward along the (111) axis. These modes of deformation should bear some resemblance to the low-energy modes responsible for the negative thermal expansion in zirconium tungstate, and thus could give some insight on the microscopic mechanism behind this phenomenon.
Contido em Physical review. B, Condensed matter and materials physics. New York. Vol. 75, no. 18 (May 2007), 184110, 7 p.
Assunto Equacoes de estado
Propriedades fisicas
Propriedades mecânicas dos materiais
Propriedades termicas
Solidos cristalinos
Origem Estrangeiro
Tipo Artigo de periódico
URI http://hdl.handle.net/10183/109085
Arquivos Descrição Formato
000603871.pdf (294.1Kb) Texto completo (inglês) Adobe PDF Visualizar/abrir

Este item está licenciado na Creative Commons License

Este item aparece na(s) seguinte(s) coleção(ões)


Mostrar registro completo

Percorrer



  • O autor é titular dos direitos autorais dos documentos disponíveis neste repositório e é vedada, nos termos da lei, a comercialização de qualquer espécie sem sua autorização prévia.
    Projeto gráfico elaborado pelo Caixola - Clube de Criação Fabico/UFRGS Powered by DSpace software, Version 1.8.1.