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 1H NMR. In TG analyses, both compounds exhibited sharp decomposition curves, with major mass losses in the region of 200–250 °C. PZT films were fabricated from one of the newly prepared Pb(IV) precursors by an MOCVD process involving Ti(OiPr)4 and Zr(OPr)4, and the development of the perovskite phase with temperature was monitored by an XRD method.