An investigation into the growth of magnesium niobium oxide and lead magnesium niobate by liquid-injection MOCVD using a magnesium–niobium alkoxide precursor
✍ Scribed by Hywell O Davies; Anthony C Jones; Timothy J Leedham; Peter J Wright; Michael J Crosbie; Penelope A Lane; Alexander Steiner; Jamie Bickley
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 77 KB
- Volume
- 10
- Category
- Article
- ISSN
- 1616-301X
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✦ Synopsis
The double metal alkoxide Mg[Nb(OEt) 6 ] 2 (2EtOH) has been in investigated as a single-source precursor for the deposition of magnesium niobium oxide and lead magnesium niobate by liquid-injection MOCVD. The presence of Pb(thd) 2 (thd = 2,2,6,6-tetramethylheptane-3,5-dionate) has been shown to significantly influence the deposition chemistry of the Mg/Nb alkoxide precursor. In the absence of Pb(thd) 2 and at low substrate temperatures (½425 °C) the Mg : Nb ratio in the oxide film grown from Mg[Nb(OEt) 6 ] 2 (2EtOH) is close to 1 : 2. At higher substrate temperatures (600 °C) the films are magnesium deficient, indicating partial decomposition of Mg[Nb(OEt) 6 ] 2 (2EtOH). However, in the presence of Pb(thd) 2 , films grown from Mg[Nb(OEt) 6 ] 2 (2EtOH) at low temperature (425-500 °C) contain no detectable Mg, whilst the 1 : 2 Mg : Nb ratio, required for Pb(Mg 0.33 Nb 0.66 )O 3 , is now obtained at higher substrate temperatures (600 °C). This is attributed to the formation of a thermally-stable Mg b-diketonate species via a gas-phase ligand exchange reaction between Pb(thd) 2 and Mg[Nb(OEt) 6 ] 2 (2EtOH).