Synthesis and characterization of lead (IV) precursors and their conversion to PZT materials through a CVD process

Abstract

New Pb(IV) precursors for lead zirconate titanate (PZT) thin films were synthesized, and their solid-state structures were elucidated by single-crystal X-ray crystallography. First, tetraphenyl lead (Ph4Pb) was synthesized from the reaction of PbCl2 with the Grignard reagent, PhMgBr, by a published method. Two of the phenyl ligands in Ph4Pb were replaced by bromines, and then were substituted with bis (trimethylsilyl)amides (btsa) to yield Ph2Pb(btsa)(2) (1), or with 2,2.6,6-tetramethyl-3.5-heptadiketonate (thd) ligands to yield Ph2Pb(thd)(2) (2). Single crystals of these two new Pb(IV) precursors were obtained by recrystallization in hexane, and their chemical compositions were characterized by FT-IR and H-1 NMR. In TG analyses, both compounds exhibited sharp decomposition curves, with major mass losses in the region of 200-250 degrees C. PZT films were fabricated from one of the newly prepared Pb(IV) precursors by an MOCVD process involving Ti((OPr)-Pr-i)(4), and Zr(OPr)(4), and the development of the perovskite phase with temperature was monitored by an XRD method.