|
High-Power-Density Plasma Deposition of Diamond-Like
Carbons Films
YAN Pengxun, YANG Si-ze, YANG Jie, LI Qing, LI Bing, LIU Chizi, CHEN Xishen
Chin. Phys. Lett. 1994, 11 (9):
558-560
.
We present a new method utilizing a high-power-density plasma for depositing diamond-like carbon (DLC) films. The main advantage of this technique is the possibility that films with good adhesion to the substrate can be prepared under room temperature and low pressure. The DLC films are deposited on the silicon substrate successfully. The structure of the DLC films was characterized by high energy electron diffraction, scanning electron microscopy, Raman spectroscopy, x-ray photoelectron spectroscopy, and infrared absorption spectrum.
|
|
Diffusion of Silver in Nanometer Ni-B Amorphous Alloy
LI Xiangyang, CHENG Huansheng, HE Wenquan, YANG Fujia
Chin. Phys. Lett. 1994, 11 (9):
577-580
.
Diffusion of Ag in nanometer Ni-B amorphous alloy, has been studied by heavy-ion Rutherford backscattering spectroscopy. The values of the diffusion coefficient which were found at 293, 323 and 373K, are 3.5x10-l6, 4.3 x10-l5 and 5.0x10-l4 cm2/s, respectively. Moreover, small values for the activation energy, 0.58 eV, and the pre-exponential factor of the diffusion coefficient, 3.9 x10-16 cm2/s , were derived from Arrhenius plot. Finally, a possible free volume controlled diffusion mechanism was discussed.
|
|
Size Effects on the Crystallite Structure and Phase Transition in Lanthanaum-Modified Lead Titanate Nanocrystals
WANG Xiaohui, WANG Zichen, ZHAO Muyu, MENG Jinfang*, LI Jiangping*, ZOU Guangtian*
Chin. Phys. Lett. 1994, 11 (9):
581-584
.
The size effects on the crystallite structure, Raman spectra as well as phase tian-sition in lanthanum-modified lead titanate Pb1-xLaxTi1-3/4xO3(x=0.14) (PLT14) nanocrystalline powders were investigated. The results show that with decreasing grain size, the crystallite structure changes from tetragonal perovskite phase to cubic perovskite phase; the soft mode frequency at room temperature decreases, and disappears when the grain size is as small as 19nm; the phase transition temperature from ferroelectric to paraelectric shifts towards a low temperature region. The phase transition in nanocrystalline PLT14 is a second order one, which is confirmed by its dielectric constant measurement.
|
17 articles
|