Effect of oxygen pressure upon composition variation during chemical vapor deposition growth of lead titanate films from tetraethyl lead and titanium tetraisopropoxide

Ferroelectric PbTiO3Films Grown by Pulsed Liquid Injection Metalorganic Chemical Vapour Deposition

“…Hong et al [13] established that an increase of O 2 concentration in gas promotes the PbO formation resulting in higher growth rate. However, too high oxygen concentration resulted in Pb deficient films, that was explained by stabilisation of high valency Pb 3 O 4 and PbO 2 at higher O 2 partial pressures [13]. The optimum percentage of oxygen in the gas flow is highly dependent on the precursor type and its thermal stability.…”

“…In the literature, mainly liquid PbEt 4 and Ti(O i Pr) 4 compounds were used as precursors for MOCVD growth of PTO films by bubbling of carrier gas through containers of liquid precursors [5,6,[12][13][14][15][16]. However, some other pairs of Pb and Ti precursors have been also studied: Pb(thd) 2 (thd = 2,2,6,6-tetramethyl-3,5-heptanedionate) and Ti(O i Pr) 4 [17][18][19][20], (C 2 H 5 ) 3 PbOCH 2 C(CH 3 ) 3 and Ti(O i Pr) 4 [21], Pb(OAc) 2 and Ti(OnBu) 4 [22], PbEt 4 and Ti-npropoxyde [23] or PbEt 4 and TiCl 4 [24].…”

Synthesis, Structural, and Electrical Properties of Pure PbTiO3Ferroelectric Ceramics

“…An example is the formation of a PT phase with the pyrochlore structure observed during a coprecipitation synthesis experiment [12]. A more common occurrence is the formation of a two-phase mixture with TiO 2 [17]. The volatilization of PbO is known to increase markedly at temperatures above 800 ∘ C though the critical temperature is debated.…”

“…Kim et al [18] have observed that a PbO-rich PT in liquid phase is formed above 838 ∘ C, Algueró et al [19] found that at 650 ∘ C an excess of 20% PbO was required because of Pb-loss during thermal treatments of sol-gel prepared Lamodified PT thin films, whereas Ananta and Thomas [20] found that Pb volatility in PMN-PT could be minimized by careful sintering up to 1250 ∘ C. What is clear is that the loss of lead depends on particle size of constituent oxides, processing conditions, and chemical stability. The degree of Pb incorporation into the presintered crystal structure affects the volatility enormously [17]. Many groups report that loss of lead (Pb) may be minimized by sintering compacted powders in a surrounding lead-based powder or a PbO vapor atmosphere [18,21] although this may lead to a Pb gradient in the final sintered product [17].…”

“…The degree of Pb incorporation into the presintered crystal structure affects the volatility enormously [17]. Many groups report that loss of lead (Pb) may be minimized by sintering compacted powders in a surrounding lead-based powder or a PbO vapor atmosphere [18,21] although this may lead to a Pb gradient in the final sintered product [17]. The problem of porosity has largely been addressed through particle size control of the starting powder.…”