Misted Deposition of [3D] Trenches for Drams and Frams III. PZT Thin Films and PZT Nanotubes
Pb(Zr,Ti)O3 (PZT) thin films and nanotube were prepared on SiO2/Si substrates by liquid source misted chemical deposition (LSMCD) using Samco MD-6060 apparatus. We report the deposition and characterization of transparent ferroelectric thin films and nanotubes. PZT thin films deposited at ambient conditions and annealing at 700degC exhibit good ferroelectric properties with remanent polarisation of ca. 15 muC/cm2. The step coverage was 59% on the side wall and 79% on the bottom wall.
Morphological Control of Polar Orientation in Single-Crystal Ferroelectric Nanowires
In an attempt to explore and understand domain configurations that occur in idealized ferroelectric nanowires, a focused ion beam microscope has been used to directly cut columns in a variety of sizes from single-crystal barium titanate. The scanning transmission electron microscope has then been used to image the ferroelectric domain patterns evident after cooling through the Curie temperature in the vacuum environment of the electron microscope. As the overall length of the wires is physically constrained, the observed length-conserving packets of 90° domains with {110}pseudocubic domain-wall orientations can easily be rationalized. Such domain structures necessarily dictate that although half of the domains can be such that their polarization direction lies parallel to the axis of the wire, the other half of the domains will have polarization directions approximately perpendicular to the wire axis (nonaxial). This situation introduces a depolarizing field and associated energy, which is minimized when ...
Synthesis and characterization of nanosized SrBi2Ta2O9 powder by a novel sol–gel process
Chemically homogeneous SrBi{sub 2}Ta{sub 2}O{sub 9} (SBT) sol was synthesized using ethoxy tantalum, strontium acetate, and bismuth subnitrate as starting materials, methoxyethylene as a solvent and acetic acid (HOAc) as a catalyst. Single-phased perovskite phase SBT ferroelectric ultrafine powder was obtained after the dried gel was treated at 350 deg. C for 30 min and calcined at 800 deg. C for 1 h. FT-IR, XRD, TEM and TG-DTA were employed to investigate the transformation processes of sol to gel and gel to ultrafine SBT powder. Acetic acid not only acts as an acid catalyst, but also changes the alkoxide precursor as a ligand at a molecular level. Bidentate acetates replace OR groups and are directly bounded to the tantalum, leading to the formation of Ta (OR){sub x}(OAc){sub 5-x}. The perovskite SBT phase formed via intermediate phase Bi{sub 3}TaO{sub 7} and a Bi-deficient pyrocholore phase.