Adhesion and mechanical properties of amorphic diamond films prepared by a laser plasma discharge source

Abstract

Amorphic diamond films can be grown in an ultrahigh vacuum environment free from hydrogen with a laser plasma discharge source. This technique produces films that adhere more readily to materials for which there are important applications as protective coatings. In this work adhesion and mechanical properties of amorphic diamond films have been examined. A beam bending method has been used to measure the internal stress and a relatively low value of compressive stress was found. The dependence of stress on the laser intensities at the graphite ablation target has been studied. Analyses of these films on silicon, SiO2, ZnS, and TiAl6V4 by Rutherford backscattering spectrometry show significant interfacial layers with compositions of SiC, C0.5SiO2, C2.5ZnS, and C0.62Ti0.35Al0.05V0.02, respectively. Adhesion properties on ZnS and other substrates have also been examined for harsh environments. The mechanical properties of hardness, Young’s modulus, and stiffness have been obtained with a nanoindentation technique. These results together with the minimal amount of hydrogen in our process, make amorphic diamond an excellent candidate for direct deposition on several substrates including ZnS.

Adhesion properties of amorphic diamond films deposited on zinc sulfide substrates

“…The diamond characteristics of these novel materials have been evaluated by several analytical methods. Measurements agree in supporting s p contents of better than 75% for the nominally produced films [3,5,6]. No other technique has been reported for the production of this material, and to date, the quenching of C+ beams available from the conventional ion beam methods onto a substrate has been shown to produce only low-quality carbon films [4,7].…”

“…Amorphic diamond films have been produced by accelerating and quenching an intense laser plasma of C3+ and C4+ onto a cold substrate [1][2][3][4][5][6][7][8][9][10]. Prepared entirely without hydrogen, fluorine, or any other catalyst, these films are composed of hard dense nodules with grain sizes of the order of 20-100 nm.…”

Calculation of the lifetimes of thin stripper targets under bombardment of intense pulsed ions

“…4, which can be attributed to the difference in the beam time structure. More exact evaluation of SNS stripper foil lifetime can be obtained by refining the differential equations (23) to account for the thermal conductivity and beam intensity distribution across the hot spot. A detailed computer simulation of the SNS foil temperature distribution is presented in Ref.…”

“…(23) and (24) was made by numerical methods by means of the program MATLAB7.0 (The MathWorks, Inc.). In Fig.…”

“…In Ref. [19] for carbon nanotubes M 1000 GPa, and the ultimate strength for nanotubes and diamond is P 100 Gpa; [23]. The decreasing quantity of a diamondlike phase gives rise to a decrease of the elastic modulus.…”