THE Tb‒Hf‒Al‒Si SYSTEM (600 °C)

N. Muts, I. Malanchuk, Ya. Tokaychuk, R. Gladyshevskii


DOI: http://dx.doi.org/10.30970/vch.6301.041

Abstract


Information about systematic investigations of quaternary intermetallic systems with rare-earth elements is scarce, therefore studies of such systems are relevant. Alloys of the Tb‒Hf‒Al‒Si system are promising for the creation of new functional materials thanks to their mechanical (due to the presence of Al in the samples), heat-resistant (Hf), semiconductor (Si), magnetic, superconducting, catalytic, and sorption (Tb) properties.

The aim of this work was to investigate the Tb‒Hf‒Al‒Si system: establish the phase composition of alloys, search for new phases and determine their crystal structures.

Samples of the Tb‒Hf‒Al‒Si system were prepared by arc-melting the elements under a purified argon atmosphere. The alloys were annealed at 600 °C for 7 months in evacuated quartz ampoules, and subsequently quenched in cold water. X-ray powder diffraction data were recorded on a DRON 2.0M diffractometer, Fe Kα radiation, a Panalytical X’Pert, Cu Kα radiation, and a STOE Stadi P diffractometer, Cu Kα1 radiation. Energy-dispersive X-ray analyses were performed on a Tescan Vega 3 LMU scanning electron microscope.

During the investigation of the Tb‒Hf‒Al‒Si system the formation of the quaternary phase (Tb0.74Hf0.26)(Al0.48Si0.52) was established based on X-ray diffraction and energy-dispersive X-ray analysis. The crystal structure of this phase belongs to the TlI type (Pearson symbol oS8, space group Cmcm, unit cell parameters: а = 4.312(1), b = 10.793(3), c = 3.973(1) Å) with a statistical mixture of Tb and Hf atoms on the I site and a statistical mixture of Al and Si atoms on the Tl site. Based on the results obtained here, the existence in the quaternary system Tb‒Hf‒Al‒Si of extended solid solutions based on other binary, Hf5Si3 (structure type Mn5Si3, Pearson symbol hP16, space group P63/mcm, 10 at. % Tb and 7 at. % Al – (Tb0.16Hf0.84)5(Al0.19Si0.81)3), TbAl2 (MgCu2, cF24, Fd-3m, 7 at. % Si – (Tb0.94Hf0.06)(Al0.90Si0.10)2), TbAl (DyAl, oP16, Pbcm, 8 at. % Hf and 5 at. % Si – (Tb0.85Hf0.15)(Al0.89Si0.11)), HfSi (FeB, oP8, Pnma, 9 at. % Tb and 7 at.% Al – (Tb0.17Hf0.83)(Al0.15Si0.85)), and ternary, Tb2Hf3Si4 (Sc2Re3Si4, tP36, P41212, 18 at. % Al – (Tb2.4Hf2.6(Al0.42Si0.58)4), compounds was established. Within the homogeneity ranges of the solid solutions, the value of the valence electron concentration does practically not change.

 Keywords: Tb‒Hf‒Al‒Si system, X-ray diffraction, energy-dispersive X-ray analysis, solid solution, TlI structure type.


References


Villars P., Cenzual K., Daams J. L. C., Hulliger F., Okamoto H., Osaki K., Prince A., Iwata S. Pauling File. Inorganic Materials Database and Design System // Crystal Impact (Distributor). Germany, 2001.

Bulanova M. V., Mikolenko A. N., Meleshevich K. A., Effenberg G., Saltykov P. A. Terbium-silicon system // Z. Metallk. 1999. Bd. 90, No. 3. S. 216‒222. DOI: https://www.osti.gov/etdeweb/biblio/336232

Gokhale A. B., Abbaschian G. J. Hf–Si (hafnium–silicon) system // Bull. Alloy Phase Diagr. 1989. Vol. 10, No. 3. P. 390‒396. DOI: https://doi.org/10.1007/BF02877595

Villars P., Cenzual K. (Eds.) Pearson’s Crystal Data – Crystal Structure Database for Inorganic Compounds // ASM International: Materials Park, OH, USA, Release 2019/20.

Tyvanchuk A.T. The ternary systems Al‒{La, Ce, Pr, Nd, Gd, Tb, Dy, Ho, Lu}‒{Zr, Hf, Nb} in the range 66.7‒100 at. % aluminum // Abstr. Cand. Sci. Thesis (Inorg. Chem.). Lviv, 1979. 24 p. (in Russian).

Muts N., Manyako M., Lasocha W., Gladyshevskii R. The Tb–Hf–Si system at 873 K // Chem. Met. Alloys. 2009. Vol. 2. P. 187‒193. DOI: https://doi.org/10.30970/cma2.0115

Melnyk I., Pikus S., Semus’o N., Gladyshevskii R. Phase diagrams of the Ln‒Al‒{Si,Ge} systems // Arch. Nauki Mater. 2004. Vol. 25, No. 2. P. 113‒131.

Rodriguez–Carvajal J. Recent developments of the Program FULLPROF // Commission on Powder Diffraction (IUCr). Newsletter, 2001. Vol. 26. P. 12–19.

Parthé E., Gelato L., Chabot B., Penzo M., Cenzual K., Gladyshevskii R. TYPIX Standardized Data and Crystal Chemical Characterization of Іnorganic Structure Types. Vol. 1–4. Heidelberg : Springer‒Verlag, 1993. P. 1596.

Muts N., Gladyshevskii R. CrB-type phases in the Tb–Zr–Al–Si system // Z. Anorg. Allg. Chem. 2006. Vol. 632. P. 2345‒2349. DOI: https://doi.org/10.1002/zaac.200600193

Semus’o N. Z. The ternary systems {Pr, Tb} ‒Al‒ {Si, Ge}. Phase equilibria, crystal structures and electrical properties of compounds // Abstr. Cand. Sci. Thesis (Inorg. Chem.). Lviv, 2001. 24 p. (in Ukrainian).

Pötzschke M., Schubert K. Zum Aufbau einiger zu T4–B3 homologer und quasihomologer Systeme. II. Die Systeme Titan–Aluminium, Zirkonium–Aluminium, Hafnium–Aluminium, Molybdän–Aluminium und einige ternäre Systeme // Z. Metallkd. 1962. Vol. 53. P. 548‒560.

Kotur B. Ya., Ratush G. М. Isothermal cross section of the Sc–Hf–Si system at 1070 K // Izv. Akad. Nauk SSSR. Neorg. Mater. 1991. Vol. 27 (3). P. 513–516 (in Russian).


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