The functionalization of carbon nanotubes (CNTs) was carried out by using different chemical treatment methods. These functionalized CNTs were characterized by TEM image and FT-IR spectra. The CNT electrodes are measured by thermal resistivity and cyclic voltammetry experiments. The results showed that two important factors controlled the electrochemical properties of the CNT film electrode: one is the active functional group; another is activation energy of the CNT film. From our experiments, we have found the electrode of 10min nitric acid treated CNTs have the optimal peaks in relation to carboxylic acids, the highest redox peak currents, the biggest value of k0 and welldefined quasi-reversible voltammograms for redox of iron couples, in which the two factors best match.

In this article, the diameter distributions of carbon nanotube were theoretically analyzed. The carbon nanotubes were grown by microwave plasma enhanced CVD. For studying the diameter distributions of the carbon nanotubes, the thermodynamic transformation of catalytic films was theoretically considered. Therefore, a process of the formation of stable catalytic islands was supposed, in which the initial continuous catalytic films were first transformed into many critical nuclei and then became stable islands through diffusion of the critical particles, where carbon nanotubes just grew up. The island distribution expression can be derived, and under certain conditions, carbon nanotubes have similar distributions. The nanotubes grown on different catalyst films were analyzed, which showed that the nanotubes over thick films have broad diameter distributions and large mean diameters, while that over thin films have narrow diameter ranges and small diameters on average. The theoretical results were in good agreement with the experimental data.

Diamond films have been deposited on AlN substrates using hot filament chemical vapor deposition. By applying a negative bias voltage, a high diamond nucleation density on AlN substrates as high as 10 10 cm-2 has been realized. The appearance of bias current and plasma induced on the AlN surface was found critical for the enhancement of diamond nucleation density. Satisfactory adhesion of the deposited diamond films with the AlN substrates has been achieved for application purposes. q2000 Elsevier Science B.V. All rights reserved.

The magnetoresistance effect of p-type diamond films has been investigated at different temperature. Diamond films were grown by microwave plasma chemical vapor deposition. Mirror-polished p-type Si(100). was used as a substrate material. The experimental results show that a notable magnetoresistance effect in polycrystalline and heteroepitaxial semiconducting diamond films was observed. The relative changes in the resistivity of the diamond films with magnetic field strongly depended on both boron-doped concentration in the films and geometric form of the samples. The effect of disk structure was greater than that of strip-type samples, also variation in the resistivity of heteroepitaxial diamond films was greater than that of polycrystalline diamond films at same magnetic field. The magnetoresistance of p-type diamond films was decreased with increasing both boron-doped concentration and temperature. The relative changes in resistance of the heteroepitaxial diamond films with the disk structure was increased by 0.85 at room temperature under magnetic intensity of 5T, but only 0.40 for strip-type structure. The results are discussed in detail.

A rare-earth Pr-based bulk metallic glass (BMG) is obtained in the shape of rod up to 5mm in diameter by die cast. Unlike other rare-earth-based BMGs, it exhibits a distinct glass transition, the low glass transition temperature (Tg5409 K), a large and stable supercooled liquid region, and paramagnetic property. The glass transition as well as its kinetic nature and the fragility parameters of the BMG have been studied. The BMG offers an ideal model to investigate the nature of glass transition as well as the relaxation and nucleation with a large experimentally accessible time and temperature window at low temperatures.