Investigation of the phase diagrams of the Sm-Ni-Pb and Sm-Cu-Pb systems

Article abstract of DOI:10.1016/S0925-8388(02)00825-3

The phase diagrams of the Sm-Ni-Pb and Sm-Cu-Pb systems were studied using X-ray phase analysis. The Sm-Ni, Sm-Cu, Sm-Pb, Ni-Pb and Cu-Pb binary systems bounding the Sm-Ni-Pb and Sm-Cu-Pb ternary systems were also investigated. The results showed that the

Full text of DOI:10.1016/S0925-8388(02)00825-3

Journal of Alloys and Compounds 348 (2003) 146–149
L
www.elsevier.com/locate/jallcom
Investigation of the phase diagrams of the Sm–Ni–Pb
and Sm–Cu–Pb systems
*
L.D. Gulay
¨
Fachbereich Chemie der Philipps-Universitat, D-35032 Marburg, Germany
Received 16 May 2002; accepted 27 May 2002
Abstract
The phase diagrams of the Sm–Ni–Pb and Sm–Cu–Pb systems were constructed using X-ray phase analysis. Four ternary compounds
˚
˚
˚
SmNiPb (TiNiSi structure type, space group Pnma, a57.3199(3) A, b54.5769(2) A, c57.8015(3) A), Sm2Ni2Pb (Mn2AlB2 structure
˚
˚
˚
type, space group Cmmm, a54.087(1) A, b514.187(3) A, c53.716(1) A), Sm5NiPb3 (Hf5CuSn3 structure type, space group P63 /mcm,
a59.171(2) A, c56.710(1) A) and Sm12Ni6Pb (Sm12Ni6In structure type, space group Im3, a59.825(2) A) exist in the Sm–Ni–Pb
system. Two ternary compounds SmCuPb (LiGaGe structure type, space group P63mc, a54.5965(2) A, c57.4769(2) A) and Sm5CuPb3
˚
˚
˚
˚
˚
˚
˚
(Hf5CuSn3 structure type, space group P63 /mcm, a59.316(1) A, c56.6881(4) A) exist in the Sm–Cu–Pb system.
2002 Elsevier Science B.V. All rights reserved.
Keywords: Rare earth alloys; Transition metal alloys; Phase diagram; Crystal structure; X-Ray diffraction
1. Introduction
type), SmCu5 (CaCu5 structure type) and SmCu6 (CeCu6
structure type) exist in the Sm–Cu system. The existence
of the compounds Sm3Pb (unknown structure), Sm5Pb3
(Mn5Si3 structure type), Sm5Pb4 (Sm5Ge4 structure type),
Sm11Pb10 (unknown structure), SmPb2 (unknown struc-
ture), SmPb3 (AuCu3 structure type) has been reported in
literature. No compounds exist in the Ni–Pb and Cu–Pb
binary systems. Crystallographic data for the binary com-
pounds of the Sm–Ni, Sm–Cu, Sm–Pb systems are
summarized in Table 1.
The results of the investigation of the phase relations
between the components in the Sm–Ni–Pb and Sm–Cu–
Pb systems at 670 K and the crystal structures of the
ternary compounds formed in these systems are given in
the present work.
The crystal structures of the compounds SmNiPb
(TiNiSi structure type, space group Pnma) [1],
Sm2Ni2Pb (Mn2AlB2 structure type, space group Cmmm)
[2] and Sm12Ni6Pb (Sm12Ni6In structure type, space group
Im3) [3] have been reported. The existence of the
SmCuPb compound with CaIn2 structure type (space group
P63 /mmc) or LiGaGe structure type (space group P63mc)
has been reported in Refs. [4] and [5], respectively. The
crystal structure of the Sm5CuPb5 compound (Hf5CuSn3
structure type, space group P63 /mcm) has been reported in
Ref. [6].
The Sm–Ni, Sm–Cu, Sm–Pb, Ni–Pb and Cu–Pb binary
systems bounding the Sm–Ni–Pb and Sm–Cu–Pb ternary
systems have been widely investigated [7,8]. The forma-
tion of the compounds Sm3Ni (Fe3C structure type), SmNi
(CrB structure type), SmNi2 (MgCu2 structure type),
SmNi3 (NbBe3 structure type), Sm2Ni7 (LT) (Er2Co7
structure type), Sm2Ni7 (HT) (Ce2Ni7 structure type),
Sm5Ni19 (Sm5Ni19 structure type), SmNi5 (CaCu5 struc-
ture type) and Sm2Ni17 (Th2Ni17 structure type) in the
Sm–Ni binary system has been reported. According to
literature data, the compounds SmCu (CsCl structure type),
SmCu2 (CeCu2 structure type), SmCu4 (CeCu4 structure
2. Experimental details
The isothermal sections of the Sm–Ni–Pb and Sm–Cu–
Pb system at 670 K were constructed using the results of
the X-ray phase analysis of 54 and 37 binary and ternary
samples, respectively. The samples with a total mass of
about 1 g were prepared by arc melting of pure metals (the
purity of the ingredients was better than 99.9 wt.%) in a
high-purity argon atmosphere. All alloys were remelted
twice to ensure homogeneity. The mass losses after the
*E-mail address: gulay@chemie.uni-marburg.de (L.D. Gulay).
0925-8388/02/$ – see front matter
PII: S0925-8388(02)00825-3
2002 Elsevier Science B.V. All rights reserved.

L.D. Gulay / Journal of Alloys and Compounds 348 (2003) 146–149
147
Table 1
Crystallographic data for the binary compounds of the Sm–Ni, Sm–Cu and Sm–Pb systems
˚
Compound
Structure
type
Space
group
Lattice parameters (A)
Ref.
a
b
c
Sm3Ni
SmNi
SmNi2
SmNi3
Fe3C
CrB
Pnma
Cmcm
Fd3m
6.99
3.776
7.2326
5.00
4.969
4.969
5.0
5.0
5.0
5.0
4.926
8.471
3.528
4.355
–
5.07
8.060
–
9.72
10.358
6.37
4.291
[7,8]
[7,8]
[7,8]
[7,8]
[7,8]
[7,8]
[8,9]
[8,9]
[8,9]
[8,9]
[7,8]
[7,8]
[7,8]
[7,8]
[8]
MgCu2
NbBe3
Er2Co7
Ce2Ni7
Sm5Ni19
Sm5Ni19
Sm5Ni19
Sm5Ni19
CaCu5
Th2Ni17
CsCl
CeCu2
CeCu4
CaCu5
CeCu6
–
–
–
–
–
–
–
–
–
–
¯
R3m
24.59
36.53
24.35
65
97
150
190
¯
(LT) Sm2Ni7
(HT) Sm2Ni7
Sm5Ni19
Sm5Ni19
Sm5Ni19
Sm5Ni19
SmNi5
Sm2Ni17
SmCu
SmCu2
R3m
P63 /mmc
P63 /mmc
¯
P6m2
¯
R3m
¯
R3m
P6/mmm
P63 /mmc
Pm3m
Imma
Pnnm
P6/mmm
Pnma
–
–
–
–
3.980
8.049
7.372
–
–
6.929
SmCu4
SmCu5
SmCu6
Sm3Pb
–
–
4.104
10.049
[7,8]
[7,8]
[8]
5.034
–
–
Sm5Pb3
Sm5Pb4
Sm11Pb10
SmPb2
Mn5Si3
Sm5Ge4
–
P63 /mcm
Pnma
–
9.163
8.244
–
–
–
–
6.687
8.363
[7,8]
[7,8]
[8]
[8]
[8]
15.78
–
–
–
–
–
–
–
–
SmPb3
AuCu3
Pm3m
melting were less than 1 wt.%. After the melting the
samples were sealed in evacuated quartz ampoules and
annealed at 670 K during 720 h. After annealing, the
ampoules with the samples were quenched in cold water.
X-Ray powder diffraction patterns of the samples were
recorded using a DRON-2.0 powder diffractometer (Fe Ka
radiation, 20#2Q#1008, Si as internal standard). Phase
analysis was carried out. The diffraction data for the
crystal structure determination of the compounds were
collected using Siemens D5000 and HZG-4a powder
diffractometers (Cu Ka radiation, step scan mode).
Lattice parameters were calculated using a least squares
method. Crystal structure determinations were carried out
using the DBWS-9411 program [10].
(Sm5Ge4 structure type) and SmPb3 (AuCu3 structure
type) in the Sm–Pb system.
3.2. Sm–Ni–Pb and Sm–Cu–Pb ternary systems
The constructed phase diagrams for the Sm–Ni–Pb and
Sm–Cu–Pb systems at 670 K are shown in Figs. 1 and 2,
respectively. Any solubility of the third component in the
binary compounds was not observed. The formation of
four ternary compounds in the Sm–Ni–Pb system and two
ternary compounds in the Sm–Cu–Pb system was ob-
served (Table 2).
3. Results
3.1. Binary systems
The existence of the following binary compounds was
confirmed at 670 K: Sm3Ni (Fe3C structure type), SmNi
(CrB structure type), SmNi2 (MgCu2 structure type),
SmNi3 (NbBe3 structure type), Sm2Ni7 (LT) (Er2Co7
structure type), Sm5Ni19 (Sm5Ni19 structure type), SmNi5
(CaCu5 structure type) and Sm2Ni17 (Th2Ni17 structure
type) in the Sm–Ni system; SmCu (CsCl structure type),
SmCu2 (CeCu2 structure type), SmCu5 (CaCu5 structure
type) and SmCu6 (CeCu6 structure type) in the Sm–Cu
system; Sm5Pb3 (Mn5Si3 structure type), Sm5Pb4
Fig. 1. Isothermal section of the Sm–Ni–Pb system at 670 K.

148
L.D. Gulay / Journal of Alloys and Compounds 348 (2003) 146–149
Table 3
Results of the crystal structure determination of the Sm5NiPb3 compound
Compound
Sm5NiPb3
Hf5CuSn3
P63 /mcm
9.171(2)
6.710(1)
488.7(3)
9.730
Structure type
Space group
˚
a(A)
˚
c(A)
3
˚
V(A )
Calculated density (g/cm3)
Number of formula units per unit cell
Radiation and wavelength
Diffractometer
Mode of refinement
RBragg
RP
2
˚
Cu 1.54178 A
Siemens D5000
Full profile
0.0622
0.0429
RwP
0.0566
Table 4
Atomic coordinates and temperature factors for the Sm5NiPb3 compound
Fig. 2. Isothermal section of the Sm–Cu–Pb system at 670 K.
2
˚
Atom
Position
x/a
y/b
z/c
B (A)
Sm1
Sm2
Ni
6(g)
4(d)
2(b)
6(g)
0.2291(8)
1/3
0
0
2/3
0
1/4
0
0
1.4(1)
0.6(1)
1.6(3)
0.3(1)
The crystal structure of the SmNiPb compound has been
determined in Ref. [1] using X-ray powder diffraction of
the sample of respective composition annealed at 870 K. It
was determined that this compound crystallizes in TiNiSi
structure type (space group Pnma). The existence of the
compound with composition SmNiPb which crystallizes in
TiNiSi structure type was also established during the
investigation of the phase equilibria in the Sm–Ni–Pb
ternary system at 670 K.
Pb
0.6021(6)
0
1/4
Table 3, whereas atomic coordinates and temperature
factors are given in Table 4. Interatomic distances and
coordination numbers of the atoms are listed in Table 5.
The crystal structure of the Sm12Ni6Pb compound
(Sm12Ni6In structure type, space group Im3) has been
investigated using X-ray powder diffraction [3].
The existence of only two ternary compounds SmCuPb
(LiGaGe structure type, space group P63mc) [5] and
Sm5CuPb3 (Hf5CuSn3 structure, space group P63 /mcm)
[6] was confirmed during the investigation of the phase
equilibria in the Sm–Cu–Pb system at 670 K.
The existence of the Sm2Ni2Pb compound (Mn2AlB2
structure type, space group Cmmm) was determined in the
Sm–Ni–Pb system at 670 K. The crystal structure of this
compound has been determined in Ref. [2] using X-ray
powder diffraction of the sample annealed at 870 K.
The existence of the Sm5NiPb3 compound was estab-
lished during the investigation of the Sm–Ni–Pb system at
670 K. The peaks of the X-ray powder diffraction pattern
of the sample of respective composition were indexed
assuming a hexagonal unit cell with the lattice parameters:
4. Discussion
˚
˚
a59.171(2) A, c56.710(1) A. The composition of the
sample, intensities of the reflections and lattice parameters
obtained proved that this compound is isostructural with
the Hf5CuSn3 structure (space group P63 /mcm). The
results of the crystal structure determination are listed in
The formation of four ternary compounds in the Sm–
Ni–Pb system and two ternary compounds in the Sm–Cu–
Pb system was observed. The compounds SmMPb (M5
Ni, Cu) crystallize in different structure types, but their
Table 2
Crystallographic data for the ternary compounds of the Sm–Ni–Pb and Sm–Cu–Pb systems
˚
Compound
Structure
type
Space
group
Lattice parameters (A)
Ref.
[1]
a
b
c
1a
2a
3
4
1
SmNiPb
TiNiSi
Pnma
7.3199(3)
4.087(1)
9.171(2)
9.825(2)
4.5965(2)
9.316(1)
4.5769(2)
7.8015(3)
3.716(1)
6.710(1)
–
7.4769(2)
6.6881(4)
Sm2Ni2Pb
Sm5NiPb3
Sm12Ni6Pb
SmCuPb
Mn2AlB2
Hf5CuSn3
Sm12Ni6In
LiGaGe
Cmmm
P63 /mcm
Im3
P63mc
P63 /mcm
14.187(3)
[2]
b
–
–
–
–
[3]
[5]
[6]
2
Sm5CuPb3
Hf5CuSn3
a For samples annealed at 870 K.
b Present work.

L.D. Gulay / Journal of Alloys and Compounds 348 (2003) 146–149
149
Table 5
and Sm–Cu–Pb systems and their crystal structures are
similar to the respective phases of the R–M–Pb (R5rare
earth metal, M5Ni, Cu) systems reported in Refs. [1–
3,5,6,11].
˚
Interatomic distances (d, A) and coordination numbers (c.n.) of the atoms
for the Sm5NiPb3 compound
˚
Atoms
Sm1
d (A)
c.n.
22Ni
22Pb
21Pb
22Sm1
22Pb
2.689(6)
3.172(5)
3.421(9)
3.639(9)
3.695(4)
3.959(4)
13
Acknowledgements
The experimental part of this work was carried out in
the Inorganic Chemistry Department of Ivan Franko L’viv
National University (L’viv, Ukraine) and W. Trzebiatowski
Institute of Low Temperature and Structure Research,
Polish Academy of Sciences (Wrocl«aw, Poland). The
24Sm1
Sm2
26Pb
22Sm2
26Sm1
3.271(2)
3.355(1)
3.999(5)
14
6
´
author is grateful to the Sniadecki Brothers Foundation for
Ni
Pb
26Sm1
2.689(6)
the financial support of his research project in the W.
Trzebiatowski Institute of Low Temperature and Structure
Research, Polish Academy of Sciences.
22Sm1
24Sm2
21Sm1
22Sm1
22Pb
3.172(8)
3.271(2)
3.421(9)
3.695(4)
3.842(4)
11
References
crystal structures are similar. Their structure relation was
described in Ref. [5]. The relation between lattice parame-
ters of these phases can be described by the following
equations:
[1] L.D. Gulay, Ya.M. Kalychak, M. Wol«cyrz, K. L« ukaszewicz, J.
Alloys Comp. 313 (2000) 42.
[2] L.D. Gulay, Ya.M. Kalychak, M. Wo«lcyrz, J. Alloys Comp. 311
(2000) 228.
[3] L.D. Gulay, Ya.M. Kalychak, M. Wol«cyrz, K. L« ukaszewicz, J.
Alloys Comp. 311 (2000) 238.
[4] D. Mazzone, D. Rossi, R. Marazza, R. Ferro, J. Less-Common Met.
84 (1982) 301.
/Œ]3
aSmCuPb ¯ bSmNiPb ¯ cSmNiPb
cSmCuPb ¯ aSmNiPb
´
[5] L.D. Gulay, J. St©epien-Damm, M. Wol«cyrz, J. Alloys Comp. 315
(2001) 169.
The compounds Sm5MPb5 (M5Ni, Cu) belong to the
same structure type. The unit cell volume of the Sm5NiPb3
compound is smaller than the respective value for the
Sm5CuPb3 compound and correlates well with the atomic
radii of Ni and Cu.
Additionally, the compounds with compositions
Sm2Ni2Pb and Sm12Ni6Pb exist in the Sm–Ni–Pb system.
The different number of ternary compounds points to a
different character of the interaction of the components in
the Sm–M (M5Ni, Cu) system. The more complex
interaction (and the higher number of the compounds)
exists in the Sm–Ni system.
´
[6] L.D. Gulay, J. St©epien-Damm, M. Wol«cyrz, J. Alloys Comp. 319
(2001) 148.
[7] P. Villars, Pearson’s Handbook of Crystallographic Data for Inter-
metallic Phases, Vol. 1–2, ASM International, Materials Park, OH,
1997.
[8] T.B. Massalsky, Binary Alloy Phase Diagrams, Vol. 1–3, American
Society for Metals, Metals Park, OH, 1986.
[9] S. Takeda, Y. Kitano, Y. Komura, J. Less-Common Met. 84 (1982)
317.
[10] R.A. Young, A. Sakthivel, T.S. Moss, C.O. Paria-Santos, Program
DBWS-9411 for Rietveld Analysis of X-ray and Neutron Powder
Diffraction Patterns, Georgia Institute of Technology, Atlanta, GA,
1995.
[11] L.D. Gulay, M. Wol«cyrz, Pol. J. Chem. 75 (2001) 1073.
The compositions of the compounds in the Sm–Ni–Pb