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Single crystal investigation of the Yb1−xNi4Sn1+x compound
Journal of Alloys and Compounds 337 (2002) L1–L3
L
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Letter
Single crystal investigation of the Yb 12x Ni 4 Sn 11x compound a b b, C. Rizzoli , O.L. Sologub , P.S. Salamakha * a
Dipartimento di Chimica GIAF and Centro per la Strutturistica Diffrattometrica CNR, Viale delle Scienze, 43100 Parma, Italy b Department of Quantum Matter, ADSM, 1 -3 -1 Kagamiyama, 739 -8526 Higashi-Hiroshima, Japan Received 10 October 2001; accepted 25 October 2001
Abstract
] ˚ Z54, V5341.1(3) A ˚ 3, The crystal structure of the new ternary stannide Yb 12x Ni 4 Sn 11x [space group F43 m (N 216), a56.987(4) A, 23 21 r 510.171 g cm , m 554.29 mm ] was refined to R50.0217, wR250.0408 from single crystal X-ray diffraction data (automatic single crystal diffractometer Philips PW1100, MoKa radiation). The compound belongs to the MgCu 4 Sn structure type of intermetallic compounds. 2002 Elsevier Science B.V. All rights reserved. Keywords: Rare earth compounds; Transition metal compound; Crystal structure; X-Ray diffraction
1. Introduction
2. Experimental
The ternary systems R–M–Sn (R – rare earth and M – transition metals) have not been studied completely so far. Among all the R–Ni–Sn systems, only the Y, Ce, Gd and Lu containing systems were investigated systematically and the isothermal sections of the phase diagrams were constructed [1–3]. In other systems, only individual alloys were synthesized and studied with the aim of searching for new isotypic compounds. All existing data on the ternary rare earth–metal–tin systems, i.e. phase diagrams, crystal structure and physical properties of the compounds are collected in the review papers listed in Refs. [4] and [5]. Three ternary compounds have been reported earlier to exist in the Yb–Ni–Sn system: YbNiSn (TiNiSi structure ˚ b54.426 A, ˚ c5 type, space group Pnma, a56.983 A, ˚ 7.616 A) [6,7], YbNi 2 Sn (MgCu 2 Al structure type, space ˚ group Fm3 m, a56.658 A) [8], YbNi 52x Sn 11x (CeCu 4.38 In 1.62 structure type, space group Pnnm, a5 ˚ b510.276 A, ˚ c54.837 A) ˚ [9]. In this paper we 16.779 A, present an X-ray single crystal study for the new compound observed in the Ni-rich region of the Yb–Ni–Sn ternary system.
The ternary sample was synthesized by melting of the constituent elements in an Mo crucible under a high-purity argon atmosphere using a radio frequency induction furnace. The sample was heated to 14008C and was then slowly cooled to room temperature. For the X-ray single crystal data collection, a single crystal was glued on the top of a glass fiber and mounted on the goniometer head. A four circle diffractometer Philips PW 1100 with graphite monochromatized MoKa ˚ was used. The least-square radiation ( l50.71073 A) refinement of the 2u values of 24 strong and well centered reflections from the various regions of reciprocal space were used to obtain the unit-cell parameters. The data set was recorded at room temperature in an v –2u scan mode. The intensities were corrected for absorption, polarization and Lorentz effect. Further details are listed in Table 1.
*Corresponding author. E-mail address: [email protected] (P.S. Salamakha).
3. Results
] The structure was solved in the space group F43 m [10] by means of direct methods revealing the positions of all atoms applying the program SHELXS-86 [11]. The structure was refined by a full-matrix least-squares program using atomic scattering factors provided by the program packages SHELXL-93 [12] and SHELXL-97 [13]. The absorption correction was performed with the assistance of
0925-8388 / 02 / $ – see front matter 2002 Elsevier Science B.V. All rights reserved. PII: S0925-8388( 01 )01919-3
C. Rizzoli et al. / Journal of Alloys and Compounds 337 (2002) L1 –L3
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Table 1 Parameters for the single crystal X-ray data collections Compound Space group [10] Lattice parameters ˚ a, A Formula per unit cell ˚3 Cell volume, A Calculated density, g cm 23 Linear absorption coefficient, mm 21 Number of measured reflections Maximum scattering angle, degrees hkl range Number of unique reflections Number of reflections with Fo .4s (Fo ) Number of refined parameters BASF R, wR2 Goodness of fit ˚ 23 ) Highest / lowest residual electron density (e, A
Yb 12x Ni 4 Sn 11x ] F43 m (216) 6.987(4) 4 341.1(3) 10.171 54.29 320 68.67 211#h#11, 0#k#11, 0#l#11 72 (R int 50.0675) 71 9 0.299(15) 0.0217, 0.0408 1.157 1.23 / 21.42
the program ABSORB [14]. The weighting schemes included a term, which accounted for the counting statistics, and the parameter correcting for isotropic secondary extinction was optimized. For all atoms the anisotropic displacement parameters were refined. A refinement of the Flack parameter indicated twinning by inversion. Subsequently the inversion twin matrix was introduced and a batch scale factor was refined to BASF50.299(15). Although the structure refinement converged to low residuals R150.0289 and wR250.0478 for the ideal composition YbNi 4 Sn, the high value of the displacement parameter for the Yb atom indicated feasible occupation of the Yb site by a statistical mixture (Yb1Sn). The latter assumption was confirmed during refinement: the residual values R1 and wR2 decreased to 0.0217 and 0.0408, respectively (Table 1), and the real composition for the compound was established as Yb 0.922(1) Ni 4 Sn 1.078( 1) . The final structural data for the Yb 12x Ni 4 Sn 11x (x5 0.078) compound are given in Table 2. The atomic coordinates were standardized using the program STIDY [15]. The interatomic distances for the Yb 12x Ni 4 Sn 11x compound are close to the values characteristic for the ˚ Yb– intermetallic compounds [16]: Yb–Sn 3.0295(13) A, ˚ ˚ Ni 2.8979(17) A, Sn–Ni 2.8955(17) A, Ni–Ni 2.4591(32) ˚ and 2.4815(32) A. ˚ A The crystal structure of the Yb 12x Ni 4 Sn 11x compound is shown in Fig. 1. The compound belongs to the MgCu 4 Sn structure type,
Fig. 1. The crystal structure of the Yb 12x Ni 4 Sn 11x compound.
which is an ordered variant of the binary AuBe 5 compound. Only two isotypic compounds were earlier found to exist in the R–Ni–Sn systems, LuNi 4 Sn [5] and ScNi 4 Sn [17] whereas no reports were presented heretofore about the formation and crystal structure of the isostoichiometric compounds with other rare earths. In the related systems
Table 2 Atomic coordinates and isotropic parameters for the compound Yb 12x Ni 4 Sn 11x Atom
Wyckoff position
x
y
z
˚2 Beq. 310 2 , A
Yb* Ni Sn
2(a) 16(e) 2(c)
0 0.62557(14) 0.25
0 0.62557(14) 0.25
0 0.62557(14) 0.25
0.567(29) 0.133(34) 0.318(35)
*0.922(1) Yb10.078(1) Sn.
C. Rizzoli et al. / Journal of Alloys and Compounds 337 (2002) L1 –L3
with other p-elements, the compounds of this structure type were observed for R–Ni–In [18] and were reported not to form with Al, Ga, Si and Ge [19,20].
Acknowledgements The authors are thankful to Dr. Jung for sample preparation. The work of O.S. was supported by a JSPS fellowship.
References [1] R.V. Skolozdra, L.P. Komarovskaya, Izv. Akad. Nauk. SSSR, Metally 2 (1988) 214. [2] R.V. Skolozdra, L.P. Komarovskaya, Izv. Akad. Nauk. SSSR, Metally 3 (1988) 199. [3] R.V. Skolozdra, L.P. Komarovskaya, O.E. Koretskaya, Ternury systems R-Ni-Sn, in: IV Vsesojuznoje Soveshchanije, Diagrammy Sostoyanija Metalicheskikh Sistem, Tezisy Dokladov, Nauka, Moscow, 1982, p. 99. [4] R.V. Skolozdra, Stannides of the Rare Earth and Transition Metals, Svit, Lviv, 1993. [5] R.V. Skolozdra, K. Gschneidner, L. Eyring, (Eds.), Handbook of Physics and Chemistry of Rare Earths Vol. 24, North-Holland Pub. Co, Amsterdam, 1997, pp. 399–517 [6] A.E. Dwight, J. Less-Common Met. 93 (1983) 411.
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[7] R.V. Skolozdra, O.E. Koretskaya, Yu.K. Gorelenko, Izv. Akad. Nauk. SSSR, Neorg. Mater. 20 (1984) 604. [8] R.V. Skolozdra, L.P. Komarovskaya, Ukr. Fiz. Zh. 28 (1983) 1093. [9] R.V. Skolozdra, R. Szymchak, H. Szymchak, L. Romaka, M. Baran, J. Phys. Chem. Solids 57 (1996) 357. [10] T. Hahn (Ed.), International Tables for Crystallography, SpaceGroup Symmetry, Vol. A, D. Reidel, Dordrecht, 1983. [11] G.M. Sheldrick, SHELXS-86, Program for Crystal Structure De¨ ¨ termination, University of Gottingen, Gottingen, 1986. [12] G.M. Sheldrick, SHELXS-93, Program for Crystal Structure Refine¨ ¨ ment, University of Gottingen, Gottingen, 1993. [13] G.M. Sheldrick, SHELXS-97, Program for Crystal Structure Refine¨ ¨ ment, University of Gottingen, Gottingen, 1997. [14] F. Ugozzoli, Comput. Chem. 11 (1987) 109. ´ L. Gelato, B. Chabot, M. Penzo, K. Cenzual, R. [15] E. Parthe, Gladyshevskii, TYPIX. Standardized data and crystal chemical characterization of inorganic structure types, in: 8th Edition, Gmelin Handbook of Inorganic and Organometallic Chemistry, Vol. 1, Springer-Verlag, Berlin, 1993. [16] W.B. Pearson, in: Crystal Chemistry and Physics of Metals and Alloys, Vol. 1, Mir, Moscow, 1977, p. 420. [17] B.Ya. Kotur, I.P. Kluchka, Izv. Akad. Nauk. SSSR, Neorg. Mater. 25 (1989) 594. [18] V.I. Zaremba, V.M. Baranyak, Ya.M. Kalychak, Vestn. Lvov. Univ. v. 25 (1984) 13. [19] E.I. Gladyshevsky, O.I. Bodak, V.K. Pecharsky, in: K. Gschneidner L. Eyring (Eds.), Handbook of Physics and Chemistry of Rare Earths, Vol. 13, North-Holland Pub. Co, Amsterdam, 1997 [20] P.S. Salamakha, O.L. Sologub, O.I. Bodak, in: K. Gschneidner, L. Eyring (Eds.), Handbook of Physics and Chemistry of Rare Earths, Vol. 27, North-Holland Pub. Co, Amsterdam, 1999.
L
www.elsevier.com / locate / jallcom
Letter
Single crystal investigation of the Yb 12x Ni 4 Sn 11x compound a b b, C. Rizzoli , O.L. Sologub , P.S. Salamakha * a
Dipartimento di Chimica GIAF and Centro per la Strutturistica Diffrattometrica CNR, Viale delle Scienze, 43100 Parma, Italy b Department of Quantum Matter, ADSM, 1 -3 -1 Kagamiyama, 739 -8526 Higashi-Hiroshima, Japan Received 10 October 2001; accepted 25 October 2001
Abstract
] ˚ Z54, V5341.1(3) A ˚ 3, The crystal structure of the new ternary stannide Yb 12x Ni 4 Sn 11x [space group F43 m (N 216), a56.987(4) A, 23 21 r 510.171 g cm , m 554.29 mm ] was refined to R50.0217, wR250.0408 from single crystal X-ray diffraction data (automatic single crystal diffractometer Philips PW1100, MoKa radiation). The compound belongs to the MgCu 4 Sn structure type of intermetallic compounds. 2002 Elsevier Science B.V. All rights reserved. Keywords: Rare earth compounds; Transition metal compound; Crystal structure; X-Ray diffraction
1. Introduction
2. Experimental
The ternary systems R–M–Sn (R – rare earth and M – transition metals) have not been studied completely so far. Among all the R–Ni–Sn systems, only the Y, Ce, Gd and Lu containing systems were investigated systematically and the isothermal sections of the phase diagrams were constructed [1–3]. In other systems, only individual alloys were synthesized and studied with the aim of searching for new isotypic compounds. All existing data on the ternary rare earth–metal–tin systems, i.e. phase diagrams, crystal structure and physical properties of the compounds are collected in the review papers listed in Refs. [4] and [5]. Three ternary compounds have been reported earlier to exist in the Yb–Ni–Sn system: YbNiSn (TiNiSi structure ˚ b54.426 A, ˚ c5 type, space group Pnma, a56.983 A, ˚ 7.616 A) [6,7], YbNi 2 Sn (MgCu 2 Al structure type, space ˚ group Fm3 m, a56.658 A) [8], YbNi 52x Sn 11x (CeCu 4.38 In 1.62 structure type, space group Pnnm, a5 ˚ b510.276 A, ˚ c54.837 A) ˚ [9]. In this paper we 16.779 A, present an X-ray single crystal study for the new compound observed in the Ni-rich region of the Yb–Ni–Sn ternary system.
The ternary sample was synthesized by melting of the constituent elements in an Mo crucible under a high-purity argon atmosphere using a radio frequency induction furnace. The sample was heated to 14008C and was then slowly cooled to room temperature. For the X-ray single crystal data collection, a single crystal was glued on the top of a glass fiber and mounted on the goniometer head. A four circle diffractometer Philips PW 1100 with graphite monochromatized MoKa ˚ was used. The least-square radiation ( l50.71073 A) refinement of the 2u values of 24 strong and well centered reflections from the various regions of reciprocal space were used to obtain the unit-cell parameters. The data set was recorded at room temperature in an v –2u scan mode. The intensities were corrected for absorption, polarization and Lorentz effect. Further details are listed in Table 1.
*Corresponding author. E-mail address: [email protected] (P.S. Salamakha).
3. Results
] The structure was solved in the space group F43 m [10] by means of direct methods revealing the positions of all atoms applying the program SHELXS-86 [11]. The structure was refined by a full-matrix least-squares program using atomic scattering factors provided by the program packages SHELXL-93 [12] and SHELXL-97 [13]. The absorption correction was performed with the assistance of
0925-8388 / 02 / $ – see front matter 2002 Elsevier Science B.V. All rights reserved. PII: S0925-8388( 01 )01919-3
C. Rizzoli et al. / Journal of Alloys and Compounds 337 (2002) L1 –L3
L2
Table 1 Parameters for the single crystal X-ray data collections Compound Space group [10] Lattice parameters ˚ a, A Formula per unit cell ˚3 Cell volume, A Calculated density, g cm 23 Linear absorption coefficient, mm 21 Number of measured reflections Maximum scattering angle, degrees hkl range Number of unique reflections Number of reflections with Fo .4s (Fo ) Number of refined parameters BASF R, wR2 Goodness of fit ˚ 23 ) Highest / lowest residual electron density (e, A
Yb 12x Ni 4 Sn 11x ] F43 m (216) 6.987(4) 4 341.1(3) 10.171 54.29 320 68.67 211#h#11, 0#k#11, 0#l#11 72 (R int 50.0675) 71 9 0.299(15) 0.0217, 0.0408 1.157 1.23 / 21.42
the program ABSORB [14]. The weighting schemes included a term, which accounted for the counting statistics, and the parameter correcting for isotropic secondary extinction was optimized. For all atoms the anisotropic displacement parameters were refined. A refinement of the Flack parameter indicated twinning by inversion. Subsequently the inversion twin matrix was introduced and a batch scale factor was refined to BASF50.299(15). Although the structure refinement converged to low residuals R150.0289 and wR250.0478 for the ideal composition YbNi 4 Sn, the high value of the displacement parameter for the Yb atom indicated feasible occupation of the Yb site by a statistical mixture (Yb1Sn). The latter assumption was confirmed during refinement: the residual values R1 and wR2 decreased to 0.0217 and 0.0408, respectively (Table 1), and the real composition for the compound was established as Yb 0.922(1) Ni 4 Sn 1.078( 1) . The final structural data for the Yb 12x Ni 4 Sn 11x (x5 0.078) compound are given in Table 2. The atomic coordinates were standardized using the program STIDY [15]. The interatomic distances for the Yb 12x Ni 4 Sn 11x compound are close to the values characteristic for the ˚ Yb– intermetallic compounds [16]: Yb–Sn 3.0295(13) A, ˚ ˚ Ni 2.8979(17) A, Sn–Ni 2.8955(17) A, Ni–Ni 2.4591(32) ˚ and 2.4815(32) A. ˚ A The crystal structure of the Yb 12x Ni 4 Sn 11x compound is shown in Fig. 1. The compound belongs to the MgCu 4 Sn structure type,
Fig. 1. The crystal structure of the Yb 12x Ni 4 Sn 11x compound.
which is an ordered variant of the binary AuBe 5 compound. Only two isotypic compounds were earlier found to exist in the R–Ni–Sn systems, LuNi 4 Sn [5] and ScNi 4 Sn [17] whereas no reports were presented heretofore about the formation and crystal structure of the isostoichiometric compounds with other rare earths. In the related systems
Table 2 Atomic coordinates and isotropic parameters for the compound Yb 12x Ni 4 Sn 11x Atom
Wyckoff position
x
y
z
˚2 Beq. 310 2 , A
Yb* Ni Sn
2(a) 16(e) 2(c)
0 0.62557(14) 0.25
0 0.62557(14) 0.25
0 0.62557(14) 0.25
0.567(29) 0.133(34) 0.318(35)
*0.922(1) Yb10.078(1) Sn.
C. Rizzoli et al. / Journal of Alloys and Compounds 337 (2002) L1 –L3
with other p-elements, the compounds of this structure type were observed for R–Ni–In [18] and were reported not to form with Al, Ga, Si and Ge [19,20].
Acknowledgements The authors are thankful to Dr. Jung for sample preparation. The work of O.S. was supported by a JSPS fellowship.
References [1] R.V. Skolozdra, L.P. Komarovskaya, Izv. Akad. Nauk. SSSR, Metally 2 (1988) 214. [2] R.V. Skolozdra, L.P. Komarovskaya, Izv. Akad. Nauk. SSSR, Metally 3 (1988) 199. [3] R.V. Skolozdra, L.P. Komarovskaya, O.E. Koretskaya, Ternury systems R-Ni-Sn, in: IV Vsesojuznoje Soveshchanije, Diagrammy Sostoyanija Metalicheskikh Sistem, Tezisy Dokladov, Nauka, Moscow, 1982, p. 99. [4] R.V. Skolozdra, Stannides of the Rare Earth and Transition Metals, Svit, Lviv, 1993. [5] R.V. Skolozdra, K. Gschneidner, L. Eyring, (Eds.), Handbook of Physics and Chemistry of Rare Earths Vol. 24, North-Holland Pub. Co, Amsterdam, 1997, pp. 399–517 [6] A.E. Dwight, J. Less-Common Met. 93 (1983) 411.
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[7] R.V. Skolozdra, O.E. Koretskaya, Yu.K. Gorelenko, Izv. Akad. Nauk. SSSR, Neorg. Mater. 20 (1984) 604. [8] R.V. Skolozdra, L.P. Komarovskaya, Ukr. Fiz. Zh. 28 (1983) 1093. [9] R.V. Skolozdra, R. Szymchak, H. Szymchak, L. Romaka, M. Baran, J. Phys. Chem. Solids 57 (1996) 357. [10] T. Hahn (Ed.), International Tables for Crystallography, SpaceGroup Symmetry, Vol. A, D. Reidel, Dordrecht, 1983. [11] G.M. Sheldrick, SHELXS-86, Program for Crystal Structure De¨ ¨ termination, University of Gottingen, Gottingen, 1986. [12] G.M. Sheldrick, SHELXS-93, Program for Crystal Structure Refine¨ ¨ ment, University of Gottingen, Gottingen, 1993. [13] G.M. Sheldrick, SHELXS-97, Program for Crystal Structure Refine¨ ¨ ment, University of Gottingen, Gottingen, 1997. [14] F. Ugozzoli, Comput. Chem. 11 (1987) 109. ´ L. Gelato, B. Chabot, M. Penzo, K. Cenzual, R. [15] E. Parthe, Gladyshevskii, TYPIX. Standardized data and crystal chemical characterization of inorganic structure types, in: 8th Edition, Gmelin Handbook of Inorganic and Organometallic Chemistry, Vol. 1, Springer-Verlag, Berlin, 1993. [16] W.B. Pearson, in: Crystal Chemistry and Physics of Metals and Alloys, Vol. 1, Mir, Moscow, 1977, p. 420. [17] B.Ya. Kotur, I.P. Kluchka, Izv. Akad. Nauk. SSSR, Neorg. Mater. 25 (1989) 594. [18] V.I. Zaremba, V.M. Baranyak, Ya.M. Kalychak, Vestn. Lvov. Univ. v. 25 (1984) 13. [19] E.I. Gladyshevsky, O.I. Bodak, V.K. Pecharsky, in: K. Gschneidner L. Eyring (Eds.), Handbook of Physics and Chemistry of Rare Earths, Vol. 13, North-Holland Pub. Co, Amsterdam, 1997 [20] P.S. Salamakha, O.L. Sologub, O.I. Bodak, in: K. Gschneidner, L. Eyring (Eds.), Handbook of Physics and Chemistry of Rare Earths, Vol. 27, North-Holland Pub. Co, Amsterdam, 1999.