Li–N dual-doped ZnO thin films prepared by an ion beam enhanced deposition method

Li-N dual-doped ZnO films [ZnO：（Li,N）] with Li doping concentrations of 3 at.%-5 at.% were grown on a glass substrate using an ion beam enhanced deposition （IBED） method. An optimal p-type ZnO：（Li,N） film with the resistivity of 11.4 Ω·cm was obtained by doping 4 at.% of Li and 5 sccm flow ratio of N2. The ZnO：（Li,N） films-exhibited a wurtzite structure and good transmittance in the visible region. The p-type conductive mechanism of ZnO：（Li,N） films are attributed to the Li substitute Zn site （Lizn） acceptor. N doping in ZnO can forms the Lii-No complex, which depresses the compensation of Li occupy interstitial site （Lii） donors for Lizn acceptor and helps to achieve p-type ZnO：（Li,N） films. Room temperature photoluminescence measurements indicate that the UV peak （381 nm） is due to the shallow acceptors Lizn in the p-type ZnO：（Li,N） films. The band gap of the ZnO：（Li,N） films has a red-shift after p-type doping.

PREPARATION OF TiN FILMS BY N_2 ASSISTED Xe^+ ION BEAM ENHANCED DEPOSITION AND THEIR MECHANICAL PROPERTIES

A new method for preparation of hard TiN films has been developed by using electron beam evaporation-deposition of Ti and bombardment with 40 keV Xe^+ ion beam in a N_2 gas environment.The synthesized TiN films were superior to PVD and CVD ones in respects of improved adhesion to substrate and low preparing temperature.They exhibited good wear resistance and high hardness up to 2200 kg/mm^2.Some industrial applications have been reported.

SYNTHESIS OF TiN FILM WITH ION BEAM ENHANCED DEPOSITION AND ITS PROPERTIES

The TiN films were synthesized with an alternate process of depositing titanium from a E-gun evaporation source and 40 keV N^+ bombarding onto the target.It is shown from the composi- tion analysis and structure investigations using RBS,AES,TEM,XPS and X-ray diffraction spectrum that the formed fihns are mainly composed of TiN phase with grain size of 30—40 nm and without preferred orientation,the nitrogen content in the film is much less than that in case without N^+ bombarding,and an intermixed region about 40 nm thick exists between the film and the substrate.The films exhibt high microhardness and low friction. ZHOU Jiankun,Ion Beam Laboratory,Shanghai Institute of Metallurgy,Academia Sinica, Shanghai 200050,China

Study on Blood Compatibility of Carbon-Nitride Film Synthesized by Ion Beam Enhanced Deposition

In this paper, blood compatibility of carbonnitride film synthesized by ion beam enhanced deposition is studied. Clotting time measurement, platelet adhesion test and surface energy determination were performed to evaluate the interaction between blood and material. The results show that carbonnitride film has better blood compatibility than titanium, and may be promising in biomaterial filed.

Influence of surface coating on Ti811 alloy resistance to fretting fatigue at elevated temperature

An extensive study of the composition distribution, bonding strength, hardness, and wear resistance of a 0Cr18Ni9 film deposited on a Ti811 titanium alloy surface by ion beam enhanced deposition （IBED） is presented. Shot peening was introduced to post-treat the modified surface to synergistically improve the fretting fatigue resistance of the Ti811 alloy at 350°C. The results indicate that the 0Cr18Ni9 film with high density, small grain size, low void radio, and high bonding strength can be prepared using IBED. As a result, the hardness, wear resistance, and fretting fatigue resistance of the Ti811 alloy are increased to a remarkable extent. Compared with shot peening treatment or IBED 0Cr18Ni9 film alone, the Ti811 titanium alloy with an IBED 0Cr18Ni9 film combined with shot peening shows a higher fretting fatigue resistance at 350°C. This is due to the synergistic effect of the high wear resistance of the film surface and the residual compressive stress induced by shot peening.