V. A. Shestakov

Topology of subsolidus isothermal sections of the phase diagrams of ternary reciprocal systems without continuous solid solutions

The topological properties were studied for isobaric-isothermal subsolidus sections of the phase diagrams of ternary reciprocal systems with phases of constant compositions or limited solid solutions. Systems with the triangulation schemes of diagonal and adiagonal types were analyzed. Relations between the topological parameters of graphs corresponding to such schemes were found. Algorithms for solving the problems of generation and enumeration of these triangulation schemes were presented. A wide diversity of types of triangulations was demonstrated. Their classification was proposed.

Topology of melting diagrams of ternary reciprocal systems without continuous solid solutions

The topological properties were considered for melting diagrams of ternary reciprocal systems with constant-composition phases or with isomorphic diagrams with limited solid solutions. An algorithm for constructing the diagrams was described, and an example was given for a melting diagram with one binary peritectic compound and two ternary stoichiometric compounds, all melting without decomposition. A problem of enumeration of all the phase diagrams with such a set of compounds was solved.

Partition of the composition tetrahedron during construction of subsolidus isobaric-isothermal sections of the phase diagrams of quaternary systems

A problem of constructing subsolidus isobaric-isothermal sections of phase diagrams with constant-composition compounds and limited solid solutions was considered. Relations between the topological characteristics of such sections were derived. Their topological classification was proposed. An algorithm for constructing sections using the theory of finite graphs was developed. A problem of enumerating sections for diagrams with a given set of classification characteristics was solved.

Calculation of phase equilibria between the gas and the solid phases in the Nb-I and He-Nb-I systems

Phase equilibria in the Nb-I and He-Nb-I systems were calculated. A P-T projection and isobaric sections of the phase diagram of the Nb-I system at 0.1 and 1 atm were constructed. Polythermal sections in the He-Nb-I system are topologically equivalent to the phase diagram of the Nb-I system but have some geometric features. The nature of such features was determined.

Thermodynamic Analysis of the Behavior of Trimethyl Borate as a Precursor for Chemical Vapor Deposition of Boron-Containing Films

The chemical vapor deposition (CVD) of boron-containing films involving the trimethyl borate precursor has been modeled in the ranges of pressures 0.03 ≤ Р, Torr ≤ 760 and temperatures 300 ≤ Т, K ≤ 2000. The CVD diagram of this system was found to feature existence fields of the following phase complexes: В + В4С, В4С + В2О3, С + В2О3 + В4С, С + В2О3, С + В2О3 + НВО2, С + НВО2, С + В4С, and a В4С phase.

Topology of the liquidus hypersurface of the phase diagrams of quaternary systems

Consideration was made of structural features of the liquidus and solidus hypersurfaces of the isobaric melting diagrams of quaternary systems with a single liquid phase and solid phases of constant compositions which undergo neither phase transitions nor decomposition into other phases while cooling. An intimate relationship between the topologies of such hypersurfaces was noted. The oriented graph of the liquidus hypersurface can be obtained from the graph of the solidus hypersurface by drawing arrows on its edges in the direction of decreasing temperature along the corresponding monovariant lines or by labeling its vertices with symbols of types of invariant reactions. An example was given for constructing different variants of the melting diagram of a system that correspond to the same topology of the solidus hypersurface.

Enumeration of Melting Diagrams of Ternary Reciprocal Systems without Continuous Solid Solutions

The topological properties were considered for melting diagrams of ternary reciprocal systems with constant-composition phases or limited solid solutions. Relations between the topological parameters of the diagrams were found. Algorithms for solving problems of generation of liquidus surface schemes and their enumeration and classification were presented.