Structure and phase composition of Nb-C deposited films

• Published in: Physics of metals and metallography 2013-05, Vol.114 (5), p.395-399
• Main Authors: Volodin, V. N., Teleushev, Yu. Zh, Zhakanbaev, E. A.
• Format: Article
• Language: English
• Subjects: Analysis; Carbon; Chemistry and Materials Science; Coatings; Coatings industry; Concentration (composition); Coprecipitation; Diffusion; Intervals; Materials Science; Metallic Materials; Niobium; Phase Transformations; Semiconductors; Solid solutions; Structure; Synthesis; Toy industry
• ISSN: 0031-918X; 1555-6190
• DOI: 10.1134/S0031918X13020130

Using the methods of ion-plasma sputtering and the coprecipitation of ultradispersed Nb and C particles, samples of Nb-C coatings have been obtained in the range of carbon concentrations of 1.9–56.6 at %. The structural analysis supports the existence of metastable solid solutions below 1.9 at % C, the direct synthesis of Nb 2 C in the range of 1.9–8.5 at % C, the presence of an amorphous phase between 8.5 and 41.7 at % C, and the direct synthesis of NbC in the range of 41.7–56.6 at % C. Thermal treatment below 900°C leads to a considerable widening of concentration intervals of Nb 2 C and NbC existence and the intervals of coexistence of these phases with other phases. The field of NbC carbide extends from 41.7 to 56.6 at %. At a concentration above 50 at % C, the carbon phase in the coating is not revealed, which is probably caused by difficulties detecting it via X-ray diffraction method. Upon cryogenic tests, a change in the polarity of conductivity from metallic to semiconductor type upon an increase in the carbon concentration has been demonstrated. The possibility of applying the technique of material formation using small particles for other systems has been mentioned.