Arrays of zinc oxide (ZnO) nanorods have been synthesized on silicon substrates by a solution route under an external voltage. They were ～102nm in diameter and grew along the c-axis. Meanwhile, ZnO nanotubes were also obtained. Some comparative experiments showed that applying the external voltage effectively improved the alignment of the ZnO nanorods and enhanced their adherence to the substrates. The role of the external voltage is discussed in terms of the electric field established in the solution and the electrochemical reaction at the cathode. The formation of the nanotubes is attributed to the decrease of the precursor concentration and the disparity between the field strengths at different parts of the ZnO nanorods.

A simple approach to fabricating tungsten trioxide robes was developed. Tungsten wires were heated at aronnd 800°С in a hnmid argon flow and hexagon-shaped robes with well faceted end and side surfaces resnlted. As observed with a scanning electron microscope (SEM), the robes were about 1um in cross-sectional dimension and 10um in length. The selected-area electron diffraction (SAED) pattern obtained in the transmission electron microscopy (TEM) study revealed that the robes were hexagonal tungsten trioxide (h-WO3) crystals. The formation of the well-faceted tubular structure is attribnted to the lateral coalescence of WO3 nanowires accompanied with a dehydration process.

Assemblies of flower like cupric oxide nanostructures (CuO nanoflowers) were synthesized directly on Cu plates in KOH solution at room temperature. These nanoflowers are believed to have been the result of processes such as oxidation, complex formation, condensation, Ostwald ripening and dissolution Each nanoflower contained a very large number of nanometer scaled flakes (petals) and each petal further branched into tips at its end. The sharpness of these tips resulted in a sufficiently high field enhancement factor. Field emission was available from the CuO nanoflowers and the turn on field was about 8.5V/um. Compared with other methods for fabricating CuO field emitter, this solution route featured remarkable simplicity and cheapness.

A lithium doped zinc oxide (ZnO) film was obtained by the anodic oxidation of a zinc sheet in a lithium hydroxide (LiOH) solution under an external DC voltage. The formation of the ZnO film on the surface of the Zn sheet is attributed to two simultaneous processes: the electrochemical oxidation of Zn to ZnO, and the chemical dissolution of ZnO. It was also confirmed that Li element was successfully introduced into the lattice of the ZnO film. The curves of the polarization versus applied field were measured to be hysteresis loops, suggesting ferroelectricity of the Li doped ZnO film. Tile remanent polarization and the coercive field of the film were measured to be 4.7x10-3Cm-2 and 1.2x10 7Vm-1 respectively. This ferroelectricity is believed to be the result of the occupation of off centered positions in oxygen tetrahedra by the Li* ions.