V.L. Kuznetsov, A. N. Usoltseva, and L. N. Mazon and nanotubes formation)(1). Selective methods of synthesis of these (2). Silicon carbide, which has many superior properties, such as hardness ind strength, high resistance to oxidation and corrosion, low coefficient of thermal expansion, and high thermal conductivity (3), can be also produced he form of whiskers using metallic cataly CARBON AND SIC DEPOSITS' FORMATION ON METAL CATALYSTS ACCORDING PHASE DIAGRAM APPROACH The careful analysis of catalytic methods of production of carbon products and Sic whiskers allows to find a lot of similarities and common steps of these very different processes at a fist glance. Fig. I demonstrates the carbon(A) nd Sic(B)deposition in terms of phase diagrams. Mention that the influence of the carbon and /or Si-C precursors'nature on the yield of final products can be discussed in terms of equilibrium concentrations of reaction products and intermediates along with kinetic stability of different products. However. these factors are not considered here Carbon deposits formation on metal catalysts can occur at high(higher than metal-carbon eutectic temperature) and moderate temperatures(from 500C up to metal-carbon eutectic temperature)(see Fig 1A). High-tempera ture route bases on the preliminary evaporation of carbon and metal sources (using arc discharge, laser ablation, and solar ovens) with the forthcoming vapor+solid c solution liquid+solid c d. solid M+solid Figure 1.(A) Metal-carbon phase diagram. Lines a'-b'-c'-d and a-b"-c"show the high temperature and moderate temperature routes of carbon deposits formation respectively(13).(B)Ni-C-Si phase diagram at 1633 K(data from Ref (14)), L, region of formation of liquid phase: A, region of coexistence of Sic and liquid hase(1); B, region of coexistence of Sic enriched with carbon and liquid phase: c, region of coexistence of solid carbon and liquid phaseand nanotubes formation) (1). Selective methods of synthesis of these products are highly desirable due to wide perspectives of their utilization (2). Silicon carbide, which has many superior properties, such as hardness and strength, high resistance to oxidation and corrosion, low coefficient of thermal expansion, and high thermal conductivity (3), can be also produced in the form of whiskers using metallic catalysts. CARBON AND SIC DEPOSITS’ FORMATION ON METAL CATALYSTS ACCORDING PHASE DIAGRAM APPROACH The careful analysis of catalytic methods of production of carbon products and SiC whiskers allows to find a lot of similarities and common steps of these very different processes at a fist glance. Fig. 1 demonstrates the carbon (A) and SiC (B) deposition in terms of phase diagrams. Mention that the influence of the carbon and/or Si –C precursors’ nature on the yield of final products can be discussed in terms of equilibrium concentrations of reaction products and intermediates along with kinetic stability of different products. However, these factors are not considered here. Carbon deposits formation on metal catalysts can occur at high (higher than metal –carbon eutectic temperature) and moderate temperatures (from 5008C up to metal –carbon eutectic temperature) (see Fig. 1A). High-tempera￾ture route bases on the preliminary evaporation of carbon and metal sources (using arc discharge, laser ablation, and solar ovens) with the forthcoming Figure 1. (A) Metal–carbon phase diagram. Lines a0 –b0 –c0 –d0 and a00 –b00 –c00show the high temperature and moderate temperature routes of carbon deposits formation respectively (13). (B) Ni –C–Si phase diagram at 1633 K (data from Ref. (14)), L, region of formation of liquid phase; A, region of coexistence of SiC and liquid phase (l); B, region of coexistence of SiC enriched with carbon and liquid phase; C, region of coexistence of solid carbon and liquid phase. 122 V. L. Kuznetsov, A. N. Usoltseva, and I. N. Mazov