Diamond-like carbon (DLC) films have recently been pursued as the protection of MEMS against their friction and wear.Plasma enhanced chemical vapor deposition (PECVD) technique is very attractive to prepare DLC coatin...Diamond-like carbon (DLC) films have recently been pursued as the protection of MEMS against their friction and wear.Plasma enhanced chemical vapor deposition (PECVD) technique is very attractive to prepare DLC coating for MEMS.This paper describes the preparation of DLC films using twinned electron cyclotron resonance (ECR) microwave PECVD process.Raman spectra confirmed the DLC characteristics of the films.Fourier-transform infrared (FT-IR)characterization indicates the carbon is bonded in the form sp~3 and sp~2 with hydrogen participating in bonding.The surface roughness of the films is as low as approximately (0.093)nm measured with an atomic force microscope.A CERT microtribometer system is employed to obtain information about the scratch resistance,friction properties,and sliding wear resistance of the films.The results show the deposited DLC films have low friction and good scratch/wear resistance properties.展开更多
The effect of hydrogen plasma treatment of iron oxide films on the growth and microstructure of carbon nanotubes(CNTs)by microwave plasma enhanced chemical vapor deposition process has been investigated.Microwave plas...The effect of hydrogen plasma treatment of iron oxide films on the growth and microstructure of carbon nanotubes(CNTs)by microwave plasma enhanced chemical vapor deposition process has been investigated.Microwave plasma was characterized in-situ using optical emission spectrometer.Morphology of the films was examined by scanning electron microscopy.Structural analysis was carried out by high resolution transmission electron microscopy(HRTEM)equipped with energy dispersive X-ray spectroscopy(EDS)and micro-diffraction attachments.It is found that oxide films without H_2 plasma pretreatment or treated for lesser time resulted in CNT films with high percentage of carbonaceous particles and with embedded particles/nanorods distributed discontinuously in the cavity of the nanotubes.The embedded particles were found to be of iron carbide(Fe-C)as confirmed by HRTEM,EDS and micro-diffraction analysis.Experimental observations suggested that the iron oxide particles had poor catalytic action for CNT growth and in-situ reduction of oxide clusters to Fe by hydrogen plasma plays a key role in discontinuous filling of the nanotubes by the catalytic particles.展开更多
文摘Diamond-like carbon (DLC) films have recently been pursued as the protection of MEMS against their friction and wear.Plasma enhanced chemical vapor deposition (PECVD) technique is very attractive to prepare DLC coating for MEMS.This paper describes the preparation of DLC films using twinned electron cyclotron resonance (ECR) microwave PECVD process.Raman spectra confirmed the DLC characteristics of the films.Fourier-transform infrared (FT-IR)characterization indicates the carbon is bonded in the form sp~3 and sp~2 with hydrogen participating in bonding.The surface roughness of the films is as low as approximately (0.093)nm measured with an atomic force microscope.A CERT microtribometer system is employed to obtain information about the scratch resistance,friction properties,and sliding wear resistance of the films.The results show the deposited DLC films have low friction and good scratch/wear resistance properties.
文摘The effect of hydrogen plasma treatment of iron oxide films on the growth and microstructure of carbon nanotubes(CNTs)by microwave plasma enhanced chemical vapor deposition process has been investigated.Microwave plasma was characterized in-situ using optical emission spectrometer.Morphology of the films was examined by scanning electron microscopy.Structural analysis was carried out by high resolution transmission electron microscopy(HRTEM)equipped with energy dispersive X-ray spectroscopy(EDS)and micro-diffraction attachments.It is found that oxide films without H_2 plasma pretreatment or treated for lesser time resulted in CNT films with high percentage of carbonaceous particles and with embedded particles/nanorods distributed discontinuously in the cavity of the nanotubes.The embedded particles were found to be of iron carbide(Fe-C)as confirmed by HRTEM,EDS and micro-diffraction analysis.Experimental observations suggested that the iron oxide particles had poor catalytic action for CNT growth and in-situ reduction of oxide clusters to Fe by hydrogen plasma plays a key role in discontinuous filling of the nanotubes by the catalytic particles.
