Naslov
An X-ray Powder Diffraction Study of Sr2LnTaCu2O8, Ln = Nd, Sm, Eu, Gd

Autori
Gržeta, Biserka ; Toraya, Hideo ; Brničević, Nevenka ; Bašic, Ivan ; Planinić, Pavica

Izvornik
Journal of applied crystallography (0021-8898) 29 (1996), 1; 37-41

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
mixed-metal oxides ; molecular structures ; Rietveld method ; semiconducting properties

Sažetak
A series of oxides of the composition Sr_2LnTaCu_2O_8, Ln = Nd, Sm, Eu, Gd has been characterized by X-ray powder diffraction. Samples are tetragonal, space group P4/mmm and isostructural with a perovskite-like phase Ba_2LnTaCu_2O_8. The unit-cell parameters have been determined using Mo or Si as internal standard. The structure of Sr_2SmTaCu_2O_8 has been refined by the Rietveld method. X-ray diffraction patterns of the samples and the crystal structure of Sr_2SmTaCu_2O_8 showed ordering of Ta and Cu ions: the octahedrally coordinated Ta ion is on the Cu(1) site, while Cu ions remain on the Cu(2) sites of the Ba_2YCu_3O_(7-delta)-type structure.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA