Structure and properties of Bi 2 Ti 2 O 7 pyrochlore type phase stabilized by lithium

Jerome Lelievre 1 Pascal Marchet 1
1 SPCTS-AXE3 - Axe 3 : organisation structurale multiéchelle des matériaux
SPCTS - Science des Procédés Céramiques et de Traitements de Surface
Abstract : A study of the Li2O - Bi2O3 - TiO2 ternary system evidenced a Bi2Ti2O7 pyrochlore phase in a large range of composition, centered on (Li1/2Bi1/2)TiO3 (LBT). This composition led to a pyrochlore phase stable up to 1100 °C, while pure Bi2Ti2O7 phase has been reported as metastable, with decomposition temperature around 600 °C. According to previous studies, this pyrochlore phase was not obtained without lithium and here only a few percent of lithium was necessary for stabilization. The structural study, performed by neutron diffraction, evidenced a cubic Fdm structure (a = 10.317 Å), similar to the one of “pure” Bi2Ti2O7 pyrochlore phase. The Li-ion is probably located on the Bi-site and is responsible for the stabilization of the pyrochlore structure. The electrical properties of the LBT composition were studied and appeared as very similar to the one of “pure” Bi2Ti2O7. Because of its large thermal stability range, this pyrochlore phase appears to be a promising material for dielectric or tunability applications.
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https://hal-unilim.archives-ouvertes.fr/hal-01680642
Contributeur : Pascal Marchet <>
Soumis le : mercredi 10 janvier 2018 - 23:34:40
Dernière modification le : mercredi 14 février 2018 - 16:21:41

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Jerome Lelievre, Pascal Marchet. Structure and properties of Bi 2 Ti 2 O 7 pyrochlore type phase stabilized by lithium. Journal of Alloys and Compounds, Elsevier, 2018, 732, pp.178 - 186. ⟨10.1016/j.jallcom.2017.10.128⟩. ⟨hal-01680642⟩

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