Analysis of phase equilibria in the Ge–P–Sn ternary system

  • Galina V. Semenova Voronezh State University 1, Universitetskaya pl., 394018 Voronezh, Russian Federation
  • Tat’yana A. Leont’eva Voronezh State University 1, Universitetskaya pl., 394018 Voronezh, Russian Federation
  • Tat’yana P. Sushkova Voronezh State University 1, Universitetskaya pl., 394018 Voronezh, Russian Federation
Keywords: phase equilibria,, Ge – P – Sn ternary system,, of sub-solidus phase separation


Objective. Great attention to compounds with a layered structure because of the possibility of formation of functional 2D materials on their basis predetermined the interest in compounds of the group AIVBV, in particular GeP. However, the high vapor pressure of phosphorus creates the complexity of the synthesis of this phase, so they use a solvent - tin or bismuth, which signifi cantly softens the conditions for obtaining samples. In this case, other phases may form, according to the nature of the equilibria in the ternary systems. This determines the relevance of research on the nature of phase equilibria in Ge – P – Sn ternary system. The purpose of this paper is to analyze the phase diagram of the Ge – P – Sn system and possible equilibrium schemes that take into account the features of binary systems that bounding this ternary system, based on an experimental study of the Sn4P3-Ge and Sn4P3-GeP polythermal cross sections.

Methods and Methodology. The samples were obtained by fusing simple substances of tin, germanium and red phosphorus in evacuated quartz ampoules. Then the alloys were annealed at a temperature 753 К for 120 hours. The study of the samples was carried out on the differential thermal analysis (DTA) setup with a programmable heating of the furnace. In our experiments, the heating rate of DTA-setup was 5 K · min–1. X-ray powder diffraction (XRD) analysis of samples was performed using a powder diffractometer ARL X’TRA with the following characteristics: CuKa-radiation, exposure step 0.06o, exposure time 3.0 seconds.

Results. As follows from the data of differential thermal analysis, the phase diagram of the Sn4P3–GeP section is a diagram of the eutectic type with the coordinates of the eutectic point of 800 K, 15 mol % Ge. An experimental study by the X-ray phase analysis of alloys whose compositions correspond to polythermal section Sn4P3–GeP made it possible to establish the nature of the phase separation of the system at temperatures below the solidus. In the system invariant peritectic equilibrium L + Ge ↔ GeP + Sn4P3  takes place, and there are also three triple eutectic points, responding to the processes L ↔ Ge + Sn + Sn4P3 ; L ↔ GeP + SnP3 + Sn4P3  and L ↔ P + GeP + SnP3

Conclusions. Taking into account the nature of phase equilibria in binary systems, two possible schemes of sub-solidus phase separation of the Ge – P – Sn ternary system diagram are proposed. The choice was made on the basis of X-ray phase analysis of samples of polythermal section Sn4P3 –GeP. It was established that the sectionґs alloys are a mixture of three phases – Sn4P3 , GeP and Ge. Accordingly, the separation of the diagram below the solidus temperature is performed by Sn4P3-Ge, Sn4P3–GeP and SnP3–GeP cuts.




  1. Castellanos-Gomez A. Why all the fuss about 2D semiconductors? Nature Photonics, 2016, v. 10, pp. 202-204.
  2. Hasan M. Z., Kane C. L. Colloquium: Topological insulators. Mod. Phys., 2010, v. 82, pp. 3045–3067.
  3. Piot P., Behrens C., Gerth C., Dohlus M., Lemery F., Mihalcea D., Stoltz P., Vogt M. Erratum: Generation and Characterization of Electron Bunches with Ramped Current Profi les in a Dual-Frequency Superconducting Linear Accelerator. Rev. Lett., 2012, v. 108, pp. 1–5.
  4. Dávila M. E., Xian L, Cahangirov S., Rubio A., Le Lay G. Germanene: a novel two-dimensional germanium allotrope akin to graphene and silicene . New J. Phys., 2014, v. 16, pp. 095002.
  5. Lalmi B., Oughaddou H., Enriquez H., Kara A., Vizzini S., Ealet B., Aufray B. Epitaxial growth of a silicene sheet. Phys. Lett., 2010, v. 97, pp. 223109. DOI: 10.1063/1.3524215
  6. Kara H., Enriquez H., Seitsonen Ari P., Lew Yan Voon L.C., Vizzini S., Aufray B., Oughaddou H. Corrigendum to “A review on silicene – New candidate for electronics”. Sci. Rep., 2012, v. 67, pp. 1–18.
  7. Barreteau C, Michon B, Besnard C, Giannini E. High-pressure melt growth and transport properties of SiP, SiAs, GeP, and GeAs 2D layered semiconductors. Cryst Growth., 2016, v. 443, pp. 75–80.
  8. Ugai Ya. A., Sokolov L.I., Goncharov E.G. P-T-X diagramma sostoyaniya sistemy GeP i termodinamika vzaimodeystviya komponentov [P-T-X GeP system state diagram and thermodynamics of componentinteraction] // Russian Journal of Inorganic Chemistry, 1978, v. 23(7), рр. 1907–1911. (in Russ.)
  9. Lee K., Synnestvedt S., Bellard M., Kovnir K. GeP and (Ge1−Sn )(P1−Ge ) (x≈0.12, y≈0.05): Synthesis, structure, and properties of two-dimensional layered tetrel phosphides. Solid State Chem., 2015, v. 224, pp. 62–70. jssc.2014.04.021
  10. Vivian A. C. Inst. Met, 1920, v. 23, pp. 325-336.
  11. Zavrazhnov A. Yu., Semenova G. V., Proskurina E. Yu., Sushkova T.P. Phase diagram of the Sn–P system. Thermal Analysis and Calorimetry, 2018, v. 134(1), pp. 475–481.
  12. Olesinski R. W., Abbaschian G. J. The Ge−Sn (Germanium−Tin) system. Bulletin of Alloy Phase Diagrams, 1984, v. 5(3), pp. 265–271.
  13. Glazov V. M., Pavlova L. M. Khimicheskaya termodinamika i fazovyye ravnovesiya [Chemical thermodynamics and phase equilibria]. Moscow, Metallurgiya Publ, 1988, 560 p. (in Russ.)
  14. Emsley J. The elements: Second Edition. Oxford University Press, Oxford, 1991.
  15. Arita M. Kamo K. Measurement of Vapor Pressure of Phosphorus over Sn–P Alloys by Dew Point Method. Jpn. Inst. Met, 1985, v. 26(4), pp. 242–250.


Download data is not yet available.

Author Biographies

Galina V. Semenova, Voronezh State University 1, Universitetskaya pl., 394018 Voronezh, Russian Federation

Semenova Galina V. — Dr. Sci. (Chem.), Full Professor, Department of General and Inorganic Chemistry,
Voronezh State University, Voronezh, Russian Federation; e-mail: semen157@                                    ORCID iD 0000- 0003-3877-985X

Tat’yana A. Leont’eva, Voronezh State University 1, Universitetskaya pl., 394018 Voronezh, Russian Federation

Leont’eva Tat’yana A. — 5th year student of the Faculty of Chemistry, Voronezh State University, Voronezh
State University, Voronezh, Russian Federation; e-mail:
ORCID iD 0000-0001-9860-2234

Tat’yana P. Sushkova, Voronezh State University 1, Universitetskaya pl., 394018 Voronezh, Russian Federation

Sushkova Tat’yana P. – Cand. Sci. (Chem.), Assistant Professor, Department of General and Inorganic
Chemistry, Voronezh State University, Voronezh, Russian Federation; e-mail:                  ORCID iD 0000-0003-1969-7082

How to Cite
Semenova, G. V., Leont’eva, T. A., & Sushkova, T. P. (2019). Analysis of phase equilibria in the Ge–P–Sn ternary system. Condensed Matter and Interphases, 21(2), 249-261.

Most read articles by the same author(s)