ИСТИНА

The investigation of the equilibrium compositions of condensed and gaseous phases for aluminum, boron, gallium, and indium phosphides was carried out using the thermodynamic modeling method. As the software program complex TERRA was used [1]. Thermodynamic modeling was carried out on condition that the heating of these substances was realized in the argon atmosphere in the temperature range 300-3000 K at different pressures from 10E2 to 10E8 Pa). The database was formed to implement the simulation. It contains the information on the thermochemical properties of the test substances in various states of aggregation: the values of the standard enthalpy, and standard entropy of formations, change of enthalpy in the range 0 - 298 K, specific heat vs. temperature, temperature and enthalpy of phase transitions. The thermodynamic values of AlP, BP, GaP, and InP compounds were calculated by the authors of this work. The information about other properties was taken from [2-6]. The temperature dependences of the equilibrium composition of the condensed and gaseous phases and thermodynamic parameters of the state for each of the studied systems were calculated in a wide range of pressures, as well as the behavior of different components was identified. The comparison of the temperature dependences of the composition of components and thermodynamic parameters showed that there is a correlation between them: the breaks on the graphs are observed at the same temperatures (see as example, Fig. 1). In our opinion, these breaks were caused by changes of the phase composition of the system. There were constructed the dependences of temperature, when the active decomposition of the AlP, BP, GaP, InP takes place, vs. common pressure. It was shown, that these dependences are linear. The obtained information allows us to determine the necessary technological modes of production materials, gives the ability to predict the properties of the resulting compounds and pure substances in real conditions, i.e., the thermodynamic studies are the basis of technology of the control synthesis of electronic materials. REFERENCES: 1.B.G. Trusov. Program system of the simulation of phase and chemical equilibrium at high temperatures. Vestnik of Bauman Moscow State Technological University, 2012, p.240-249 (Russian). 2.V.P. Vassiliev, J.-C. Gachon. Thermodynamic properties of indium phosphide (InP), Russ. Inorganic Materials 42 (2006) 1827-1292. 3.V.P. Vassiliev, J.-C. Gachon. Thermodynamic Properties of AIIIBV compounds. Russ. Inorganic Materials 42 (2006) 1293-1303. 4.V.P. Vassiliev, B. Legendre, V.P. Zlomanov. The critical analysis and mutual coherence of thermodynamic data of the AIIIBV phases, Intermetallics 19 (2011) 1891-1901. 5.H. Yokokawa, Tables of Thermodynamic Properties of Inorganic Compounds, J. Nat. Chem. Laboratory for Industry Japan, 83 (1988) 27. 6.I. Barin, O. Knacke, O. Kubashewski. Thermochemical properties of inorganic substances. Supplement. 1977. Springer – Verlag. Berlin – Heidelberg – New-York.