Mechanosynthesis and mechanical activation processes to the preparation of the Sr2[Srn−1TinO3n+1] Ruddlesden–Popper family
2004; Elsevier BV; Volume: 177; Issue: 4-5 Linguagem: Inglês
10.1016/j.jssc.2003.12.006
ISSN1095-726X
AutoresTeresa Hungrı́a, Ana B. Hungría, A. Castro,
Tópico(s)Advanced Condensed Matter Physics
ResumoA novel mechanochemical activation route has been applied in order to obtain the n=1–4 and ∞ members of the Sr2[Srn−1TinO3n+1] Ruddlesden–Popper series. The evolution of the (n+1)SrO:nTiO2 powder mixtures during mechanical treatment was followed by X-ray powder diffraction in all cases. Except for the 2SrO:TiO2 composition, SrTiO3 was always mechanosynthesized. High-energy milling of 2SrO:TiO2 sample resulted in the formation of nanosized Sr2TiO4, which is the only K2NiF4-type oxide prepared by mechanical treatment until now. The mechanical treatment was followed by annealing at different temperatures to establish the optimized protocol for synthesis of each member of the series. SrTiO3, Sr2TiO4 and Sr3Ti2O7 were obtained with very important decreases in the formation temperatures and reaction times as compared with the traditional ceramic method. Final and milled products were studied by X-ray powder diffraction at room and increasing temperatures, and by thermal analysis and scanning and high resolution transmission electron microscopy.
Referência(s)