Microstructure and fracture strength of different grades of freestanding diamond films deposited by a DC Arc Plasma Jet process

Influence of Ar/C2H2 ratio on the structure of hydrogenated carbon films

“…According to this, the longer distance will lower the plasma jet temperature and velocity. Other authors [14,20,26] also found that the growth rate of the coatings decreases by decreasing the substrate temperature.…”

“…Over the last decades many experimental researches were carried out to adjust the plasma jet CVD systems for the deposition of carbon films. Many authors, as the main advantage of the plasma jet CVD over other CVD methods, mention a possibility to deposit the amorphous hydrogenated carbon or polycrystalline diamond films at the atmospheric or reduced pressure and the attainment of high growth rate up to 30 nm/s [14][15][16][17][18][19][20][21][22][23][24]. However, the plasma chemistry in the plasma jet is very complicated and depends on many factors.…”

“…Mankelevich et al [17,18] chemical gas-phase process involves 23 species and 76 reversible reactions. It is believed that C, C 2 , CH , CH 2 , CH 3 , and C 2 H x hydrocarbon species play a main role in the diamond growth processes [14][15][16][17][18][19][20][21][22][23][24][25]. Zhou et al [25] presumed that C 2 H x is helpful to the growth of (1 1 1) crystalline surface, while CH y to that of non (1 1 1) surface.…”

“…Benedikt et al [22,23] determined that the variation of acetylene gas flow in the argon plasma stipulated different growth species; due to which a-C:H film properties could be controlled. Most of the authors agree that the content of hydrocarbon gases in plasma, the power of the arc, the pressure, the plasma velocity and temperature influence the composition and densities of various species in plasma jet and as a consequence the properties of carbon film [14][15][16][17][18][19][20][21][22][23][24][25][26]. However, most of the research of these scientists was focused on the films deposited from CH 4 gas, while there is a lack of information about the structure and properties of carbon films formed from the acetylene gas using PJCVD.…”

Newly Designed Glass Scribing Wheel Made of Chemical Vapor Deposition Diamond Film

“…The hardness of ultra‐NCD (UNCD) is close to that of bulk diamond 18 . Yang et al 19 pointed out that the fracture strength of CVDD film will be as low as 250 MPa due to the presence of columnar structures. If the proportion of (220) grains increased, the fracture strength will significantly rise to 640 MPa.…”