In a short time the scanning tunneling microscope has taken an important place in todays surface science. One of the outstanding features of the instrument is that it can study both the geometric and electronic structure of surfaces with a lateral resolution of only 2_??_3 Å. In this paper we discuss some aspects of instrumentation and we illustrate the microscope's abilities with recent results obtained on silicon surfaces.
Diamond thin films and diamond particles have been formed by thermal chemical vapor deposition (thermal CVD) using organic compounds such as CH3OH, C2H5OH, CH3COCH3, C2H5OC2H5 and (CH3)3N. These organic compounds contain a combination of C, H and 0, or that of C, H and N. The films are grown on silicon substrates with high growth rates (8-10 μm/h). Such growth rates are 10times faster than the CVD method using hydrocarbons such as CH4 and C2H3. The films have good crystallinity and high quality without graphitic and amorphous carbon in the sense of electron diffraction and Raman spectrum. The growth conditions are not particularly severe, the reaction pressure range is as wide as 1_??_800 Torr. It is considered that methyl radical (CH3) and atonic hydrogen (H) play important roles in the synthesis of diamond.
Wear and friction behavior of diamond-like-carbon (DLC) films prepared by an ion-beam sputter deposition under different conditions were studied. Plastics or magnetic films were covered by DLC films which was deposited at room temperature. The thickness of these films were about 20 nm. Double-layered DLC films (a layer of lubricant deposited by using argon ion-beam on a highly stable layer of film deposited by using argon and hydrogen ion-beam) exhibited low friction coefficient (μ=0.16) and long life time (> 103 cycles under the weight of 20 g). It was noted that the DLC thin films on the flexible substrates were highly lubricating and stable.
Electroluminescence (EL) properties of Po-tassium-Anthracene complex compound crys-tals (K-Ant) have been investigated. The steady-state EL intensity at the peak wave-length was about ten times larger than that of Anthracene crystals, the increase of spectral intensity was especially notable at the longer wavelength. Furthermore, the luminous zone (recombination region) of K-Ant along the c'axis expanded. It was found that the drift mobility of K-Ant decreased slightly along the a and b axes and increased along the c'axis by a factor of 1. 5 compared with that of Anthracene single crystals.