“…The cathode spot is particularly suitable for generating plasma comprised of refractory metallic elements (i.e., with high melting temperatures and low equilibrium vapor pressure), such as W, Nb, C, Ti, Zr, and Ta, which can then be deposited as thin films and coatings. Refractory films have been used for investigating arcing in tokamaks (on tungsten coated graphite) [8], reaction of Ti, Nb, W, Zr, and Mo films (deposited by RF sputtering) with Al 2 O 3 (motivated by microelectronics applications) [9], and properties of metal containing diamond-like carbon coatings [(Ti, Nb, and W)-DLC] deposited by magnetron sputtering [10]. Hoffman and Thornton [11] presented data for films up to 0.3-µm thick sputtered onto glass substrates at a nominal deposition rate of 1 nm/s over the pressure range 0.067-4.0 Pa of argon.…”