Materials Transactions Online

Materials Transactions, Vol.59 No.04 (2018) pp.575-579
© 2018 The Japan Institute of Metals and Materials

Isothermal Section of Ga-Ru-Cu Ternary Phase Diagram at 1073 K: Formation of New Ternary Phase, Ga4Ru3Cu, and Its Structural Relation with the GaRu β-Phase

Takanobu Hiroto1, Kazuya Honda1, Kazue Nishimoto2, Koichi Kitahara1 and Kaoru Kimura1

1Graduate School of Frontier Sciences, The University of Tokyo, Kashiwa 277-8561, Japan
2Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577, Japan

We have investigated the isothermal phase diagram of the Ga-Ru-Cu ternary system at 1073 K by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and transmission electron microscopy to determine whether the stable icosahedral quasicrystal (i-phase) forms, as it does in the similar Al-Ru-Cu system, and new intermetallic phases exist. This is the first systematic investigation of the Ga-Ru-Cu system. No stable i-phase is identified in the Ga-Ru-Cu alloy system. However, we found a new ternary (τ) phase in the Ga-Ru-Cu system, which is characterized as a C-centered orthorhombic lattice with aτ = 11.80 Å, bτ = 6.04 Å, and cτ = 3.07 Å. The (ideal) chemical composition of the τ-phase is Ga50Ru37.5Cu12.5 (Ga4Ru3Cu). This new phase is stable up to 1073 K. Above 1173 K, the τ-phase transforms to the cubic GaRu (β) phase without any secondary phases. Thus, there is an order-disorder transition between the low-temperature τ-phase and the high-temperature cubic β-phase in this temperature range.


(Received 2017/10/30; Accepted 2018/01/09; Published 2018/03/25)

Keywords: phase diagram, Ga-Ru-Cu alloy, X-ray diffraction

PDF(member)PDF (member) PDF(organization)PDF (organization) Order DocumentOrder Document Table of ContentsTable of Contents


  1. Shechtman D., Blech I., Gratias D. and Cahn J.W.: Phys. Rev. Lett. 53 (1984) 1951.
  2. Levine D. and Steinhardt P.J.: Phys. Rev. Lett. 53 (1984) 2477.
  3. Tsai A.P., Inoue A. and Masumoto T.: Jpn. J. Appl. Phys. 26 (1987) L1505.
  4. Tsai A.P., Inoue A. and Masumoto T.: Jpn. J. Appl. Phys. 27 (1988) L1587.
  5. Tsai A.P., Inoue A., Yokoyama Y. and Masumoto T.: Mater. Trans. JIM 31 (1990) 98.
  6. Mikheeva M.N., Panova G.K., Teplov A.A., Khlopin M.N., Chernopleknov N.A. and Shikov A.A.: Phys. Sol. State 42 (2000) 2177.
  7. Asao T., Tamura R. and Takeuchi S.: Philos. Mag. Lett. 82 (2002) 217.
  8. U. Mizutani: Hume-Rothery Rules for Structurally Complex Alloy Phases, (CRC Press, 2011) Chapter 1.
  9. W.B. Pearson: Crystal Chemistry and Physics of Metals and Alloys (Wiley, New York, 1972) p. 151.
  10. Grushko B. and Velikanova T.: CALPHAD: Comput. Coupling Phase Diagrams. Thermochem. 31 (2007) 217.
  11. Yokoyama Y., Inoue A. and Masumoto T.: Mater. Trans. JIM 33 (1992) 953.
  12. See, for example, Shield J.E., McCallum R.W., Goldman A.I., Gibbons P.C. and Kelton K.F.: J. Non. Cryst. Solids 153-154 (1993) 504.
  13. Schubert K., Lukas H.L., Meissner H.G. and Bhan S.: Z. Metallkd. 50 (1959) 534.
  14. Jeitschko W., Holleck H., Nowotny H. and Benesovsky F.: Monatsh. Chem. 94 (1963) 838.
  15. P.R. Subramanian: Binary Alloy Phase Diagrams, (II Ed., Ed. T.B. Massalski, Asm Intl, 1990) pp. 1410-1412.
  16. Wagner-Reetz M., Cardoso-Gil R., Prots Yu., Schnelle W. and Grin Yu.: Solid State Sciences 32 (2014) 56.
  17. Betterton J.O. and Hume-Rothery W.: J. Institute of Metals 80 (1952) 459.
  18. El Boragy M. and Schubert K.: Z. Metallkd. 63 (1972) 52.
  19. Sharma B.D. and Donohue J.: Zeitschrift fuer Kristallographie, Kristallgeometrie, Kristallphysik, Kristallchemie 117 (1962) 293.
  20. Swanson H.E., Fuyat R.K. and Ugrinic G.M.: National Bureau of Standards (U.S.), Circular 539 (1955) 1.
  21. Otte H.M.: J. Appl. Phys. 32 (1961) 1536.
  22. P.R. Subramanian: Binary Alloy Phase Diagrams, (II Ed., Ed. T.B. Massalski, Asm Intl, 1990) pp. 1467-1468.
  23. Stokhuyzen R., Brandon J.K., Chieh P.C. and Pearson W.B.: Acta Crystallogr. B 30 (1974) 2910.
  24. Momma K. and Izumi F.: J. Appl. Crystallogr. 44 (2011) 1272.


© 2018 The Japan Institute of Metals and Materials
Comments to us :