Control of crystalline structure and ferroelectric properties of Pb(ZrxTi/sub 1-X/)O3 films by pulsed laser deposition
We have investigated Pb(Zr/sub X/Ti/sub 1-X/)O/sub 3/ (PZT) films on Pt/SiO/sub 2//Si substrates formed by pulsed laser deposition (PLD) and subsequent rapid thermal annealing (RTA) under various growth conditions. X-ray diffraction analysis revealed that preferentially [100]-oriented perovskite PZT films with trigonal structure were formed after RTA from as-deposited films which had consisted of small grains with pyroclore structure. The degree of [100]-orientation of the PZT film increased with the oxygen partial pressure during PLD. The capacitors made from these films showed higher remnant polarization than those from randomly oriented films.
FABRICATION OF FERROELECTRIC PZT THIN FILMS BY LIQUID DELIVERY MOCVD USING NOVEL Zr and Ti PRECURSORS
ABSTRACT Pb(Zr,Ti)O3 (PZT) thin films were deposited by metalorganic chemical vapor deposition (MOCVD) with liquid delivery system. Lead bis(2,2,6,6,-tetramethyl 3,5-heptanedionate) [Pb(thd)2], with two novel mixed ligand precursors Zirconium bis(isopropoxy) bis(1-methoxy-2-methyl-2-propoxy) [Zr(OiPr)2(mmp)2], and Titanium bis(isopropoxy) bis(1-methoxy-2-methyl-2-propoxy) [Ti(OiPr)2(mmp)2] were used in this study. Perovskite PZT films were obtained on (111)Ir/Ti/SiO2/Si substrates at 550°C process temperature with growth rate around 5 nm/min. The deposited PZT films show ferroelectric properties. Remanent polarization was 11.4 μ C/cm2 and coercive field is around 79.9 kV/cm for PZT film of 100 nm thickness.
Cooperative Collection Development
The author discusses cooperative collection development from an historical perspective and examines some of the projects conceived and implemented during the past forty years. In many cases the projects failed even after years of concentrated effort. However, more important than these failures are new efforts that are being made. The major focus of this article is on both current regional projects and the more broadly based ARL-sponsored North American Collections Inventory Project. The author discusses these efforts and offers some specific judgments regarding the possibility that these projects will lead to a truly successful coordinated collection development project on a national basis.