Neodymium-doped Bi4Ti3O12 ~BNT! films are evaluated for use as lead-free thin-film piezoelectrics in microelectromechanical systems. Bi4Ti3O12, Bi3.25La0.75Ti3O12 , and Bi3.25Nd0.75Ti3O12 films were fabricated by chemical solution deposition on Pt/TiOx /SiO2 /Si substrates. Nd substitution promoted random orientation with low ~00l! diffraction peaks. The 1- mm-thick Bi3.25Nd0.75Ti3O12 film annealed at 750 °C exhibited a remanent polarization of 26 mC/cm2. Typical butterfly field-induced strain loops were obtained in the BNT film capacitors. The electrically induced strain is 8.431024 under the bipolar driving field of 220 kV/cm. These results show that BNT is a promising candidate for use in lead-free thin-film piezoelectrics.

Microwave plasma-enhanced chemical vapor deposition was used to grow diamond films on Ti– 6Al–4V alloy using various gas phase precursors. The results of four types of experiments with different gas mixtures are compared: ~1! 2% CH4 in H2; ~2! initial saturation of 5% CH4 in H2 followed by 2% CH4 in H2; ~3! a CO-rich mixture with a CO:H2 ratio of 8; and ~4! a hybrid mixture of 2% CH4 in H2 followed by a CO:H2 ratio of 8. The substrate temperature during deposition with CH4 /H2 mixtures was between 715 and 810 °C, and was between 550 and 600 °C when CO/H2 mixtures were used. Optical emission spectroscopy was used to monitor the excited gas-phase species in the plasma. The films were characterized by micro-Raman spectroscopy, glancing-angle x-ray diffraction, and nanoindentation. The films grown with the type ~1! mixture often exhibited good quality with high hardness ~70 GPa! but suffered from poor adhesion to the substrate. The films grown with the type ~2! mixture were of slightly lower quality and hardness ~58 GPa! but exhibited better adhesion. The films produced from the type ~3! mixture were adhered, but exhibited very low growth rates and low hardness ~18 GPa!. Finally, the films produced from the hybrid type ~4! mixture were of poor quality and suffered from poor adhesion to the substrate. The differences in interfacial phases and mechanical properties for each film are discussed and the usefulness of each gas mixture for the diamond growth is evaluated.

Vertically aligned carbon nanotubes were selectively grown at temperatures as low as 120 8C by plasma enhanced chemical vapour deposition.W e investigated the effects of acetylene, ethylene and methane as carbon source gases together with ammonia as an etchant and nickel as catalyst material.The diluted acetylene plasma gave the highest nanotube growth rate and showed the most intense C2 Swan bands in optical emission.The activation energy for the growth rate was found to be 0.23 eV, much less than for thermal chemical vapour deposition (1.2–1.5 eV).This suggests growth occurs by surface diffusion of carbon on nickel. The result allows more cost-effective nanotube production, direct growth of nanotubes onto low-temperature substrates like plastics, and could facilitate carbon nanotube integration into sensitive nanoelectronic devices.
2003 Elsevier B.V. All rights reserved.

Vertically aligned carbon nanotubes were grown selectively on patterned Ni thin films by microwave plasma-enhanced chemical vapor deposition and their field emission properties were investigated using a diode-structure. Ni thin films patterned with a form of dot-arrays were prepared using a shadow mask having an array of holes. The nanotubes were found to be well-graphitized with multiwalled structures. The measurements of field emission properties revealed that the carbon nanotube tips emitted high current density at low macroscopic electric field. The Fowler
NordheimŽF
N.plot clearly showed two characteristic regions where the current saturates at the high electric field region. It was found that the saturation behavior was caused by the adsorbates-enhanced field emission mechanism. Eliminating the adsorbates resulted in no saturation behavior, increasing turn-on field, decreasing current, and increasing field enhancement factor. Using ZnSCu,Al phosphor, very bright and uniform emission patterns were obtained

双束激光干涉仪对超薄膜的压电性能进行测试A new method for piezoelectric measurements in ferroelectric thin films using a double-beam laser interferometer is reported.

借助原子力显微镜与TF Analyzer 2000铁电分析仪联用对微区的铁电压电性能表征Direct hysteresis measurements of single nanosized ferroelectric capacitors contacted with an atomic force microscope