Crystal structure of a strontium-tantalum and a magnesium-niobium heterometal alkoxide : precursors for the MOCVD of ferroelectric oxides
In: Journal of material chemistry, Jg. 11 (2001), Heft 2, S. 544-548
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Zugriff:
The heterometal alkoxides Sr[Ta(OPr1)6]2.2Pr1OH 1 and Mg[Nb(OEt)6]2.2EtOH 2 have been structurally characterised by X-ray diffraction. Compound 1 is a precursor for the deposition of strontium bismuth tantalate (SrBi2Ta2O9) by metalorganic chemical vapour deposition (MOCVD), whilst 2 is a potential precursor for the MOCVD of lead magnesium niobate [Pb(Mg0.33Nb0.66)O3]. In this paper it is shown how the presence of Pb(thd)2 (thd = 2,2,6,6-tetramethylheptane-3,5-dionate) significantly influences the deposition chemistry of 2. In the absence of Pb(thd)2 and at low substrate temperatures (ca. 425°C) the Mg:Nb ratio in the oxide film grown from 2 is close to 1:2, whereas at higher substrate temperatures (600°C) the films are magnesium deficient, indicating partial decomposition of 2. However, in the presence of Pb(thd)2 films grown from 2 at low temperature (425-500°C) contain no detectable Mg whilst the 1: 2 Mg:Nb ratio, required in Pb(Mg0.33Nb0.66)O3, is now obtained at higher substrate temperatures (600°C). This is attributed to the formation of a thermally stable Mg β-diketonate species via a gas-phase ligand exchange reaction between Pb(thd)2 and 2.
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Crystal structure of a strontium-tantalum and a magnesium-niobium heterometal alkoxide : precursors for the MOCVD of ferroelectric oxides
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Autor/in / Beteiligte Person: | JONES, Anthony C ; DAVIES, Hywel O ; LEEDHAM, Timothy J ; WRIGHT, Peter J ; CROSBIE, Michael J ; STEINER, Alexander ; BICKLEY, Jamie F ; O'BRIEN, Paul ; WHITE, Andrew J. P ; WILLIAMS, David J |
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Zeitschrift: | Journal of material chemistry, Jg. 11 (2001), Heft 2, S. 544-548 |
Veröffentlichung: | Cambridge: Royal Society of Chemistry, 2001 |
Medientyp: | academicJournal |
Umfang: | print, 24 ref |
ISSN: | 0959-9428 (print) |
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