DIFFUSION EFFECT IN THE FORMATION PROCESS OF Cr-NITRIDE UNDER N^+ IMPLANTATION

The diffusion of nitrogen atom in Cr thin film is studied. The temperature of the film under ion beam bombarding was measured by a new method and discussed theoretically. The temperature measured by means of thin film resistor gave a same level of volume. On the basis of the conservation of energy in equilibrium state, a semi-theoretical formula has been derived. The factors ion beam assisted diffusion were discussed. The result of AES analysis indicates that the arrangement of N atoms is long and smooth. HREM analysis and dynamic resistance measurement show that the Cr-nitride formed by N^+ implantation is in the near surface layers and can not grow very deep. The assemble of N was observed by means of TEM.

tructure and Composition of Crystalline Carbon Nitride Films Synthesized by Microwave Plasma Chemical Vapor Deposition

Crystalline carbon nitride thin films were prepared on Si (100) substrates by a microwave plasma chemical vapor deposition method, using CH4/N2 as precursor gases. The surface morphologies of the carbon nitride films deposited on Si substrate at 830℃ are consisted of hexagonal crystalline rods. The effect of substrate temperature on the formation of carbon nitrides was investigated. X-ray photoelectron spectroscopy analysis indicated that the maximum value of N/C in atomic ratio in the films deposited at a substrate temperature of 830℃ is 1 .20, which is close to the stoichiometric value of C3N4. The X-ray diffraction pattern of the films deposited at 830℃ indicates no amorphous phase in the films, which are composed of β- and α-C3N4 phase containing an unidentified C-N phase. Fourier transform infrared spectroscopy supports the existence of C-N covalent bond.

Diamond Polycrystal Powder Formation Directly from Gas Phase in a Plasma Jet System

Diamond polycrystal powder has been produced directly from gas phase in an arc discharge plasma jet system.Acetylene diluted in argon was used as hydrocarbon source gas.The product was the mixture of diamond polycrystal powders and soot.The 3C cubic phase diamond which is dominant,and the mixture phases of cubic and 6H hexagonal diamond are identified in the produced diamond polycrystal powders by electron diffraction patterns.

Two-Dimensional Animal-Like Fractals in Thin Films

we present a few unique animal-like fractal patterns in ionized-clnster-beam deposited fullerene-tetracyanoquinodimethane thin films.The fractal patterns consisting of animal-like aggregates such as"fishes"and"quasi-seahorses"have been characterized by transnission electron microscopy.The results indicate that the sall aggregates ofthe aninmal-like body are composed of many single crystals whose crystalline directions are generally different.The formation of tle fractal patterns can be attributed to the cluster-diffusion-lirnited aggregation.

Two-dimensional self-organization of 1-nonanethiol-capped gold nanoparticles

A two-dimensional (2D) ordered hexagonal close-packed structure, formed by 1-nonanethiol-capped gold nanoparticles, is reported. The structure was constructed only by dipping the gold nanoparticle colloidal solution on flat substrate. The gold nanoparticles were synthesized as follows: First, AuCl4-1 was transferred from aqueous solution to toluene by the phase-transfer reagent of tetraoc-tylanunonium bromide. Then it was reduced with aqueous sodium borohydride in the presence of a given amount of 1-nonanethiol molecules which was used to control the nu-cleation and growth of the gold nanoparticles for the desired size. The experimental techniques, such as UV-Vis, FT-IR, and X-ray photoelectron spectroscopy (XPS), were employed to characterize the obtained product. Transmission electron microscopy (TEM) measurement demonstrated the size of the gold nanoparticle and the formation of two-dimensional ordered hexagonal close-packed gold nanoparticle structure.

Experimental Study on Photoemissive Thin Films With Ultrafine Particles

There are two basic kinds of photoemissive materials for the laser pulse detection.One is the photoemissive thin films containing alkali elements,such as Ag-O-Cs,Cs3Sb,[Cs]Na2KSb.F.Gex et al.proposed that the Ag-O-Cs photocathode was the onlyphotoemissive material for detecting laser pulse with the duration≤10 ps and wavelength1.06μm.Another is pure metallic thin films,such as Au,Ag and Cu.The sensitivity ofphotocathodes containing alkali elements is higher than that of others,but this kind ofthin film cannot work at temperature higher than 150℃,nor can it be exposed to theatmosphere for the exposure will make it worthless.This causes the trouble for use。