Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8032854 | Thin Solid Films | 2018 | 28 Pages |
Abstract
Nickel-containing amorphous carbon (a-C-Ni) films were deposited by magnetron sputtering of graphite and nickel. Graphite magnetron sputtering power was 1500â¯W. Nickel magnetron sputtering power changed from 0â¯W to 1000â¯W, allowing control of the Ni concentration in the films from 0 to 58â¯at.%. Growth rates of a-C-Ni films were 1.4-2.5â¯Î¼m/h. High-voltage negative pulsed bias voltage of â3â¯kV amplitude, frequency of 1â¯kHz, and pulse duration of 50-250â¯Î¼s was applied to a substrate. The chemical composition of the films was determined using Auger electron spectroscopy. The surface morphology was observed by atomic force microscopy (AFM). The film structure was characterized by Raman spectroscopy and X-ray diffractometry (XRD). The resistivity of the films was measured by a four-point probe method. Film properties that are changed by the added metal, such as structure, electrical resistivity, and hardness, were evaluated and compared with those of pure a-C films as well as with literature values for a-C-Ni films. It is shown that the resistivity of a-C films depends on the duration of the bias voltage pulses and varies from 3.4 to 7.6·10â2â¯Ohm·cm at pulse duration 50 and 250â¯Î¼s, respectively. In the case of Ni doping, the a-C-Ni film resistivity can be reduced to 6.7·10â4â¯Ohm·cm. Where Ni is included in the film in the form of Ni3C carbide, which has hexagonal (hcp) modification, the crystallite size averages 12â¯nm. The film has a columnar structure and carbon is also present as a graphite-like interlayer 3â¯nm thick between the Ni3C crystallites. At sputtering power of 600â¯W of nickel magnetron, a-C-Ni film with resistivity of 5.3·10â3â¯Ohm·cm is obtained, which can be used as a barrier layer in thermoelements based on bismuth telluride.
Related Topics
Physical Sciences and Engineering
Materials Science
Nanotechnology
Authors
A.A. Solovyev, K.V. Oskomov, A.S. Grenadyorov, P.D. Maloney,