Dy-Sb-Si system at 1100 K and ternary intermetallic phases in the Dy-Sb-Si and Gd-Sb-Si systems

Article abstract of DOI:10.1016/S0925-8388(03)00080-X

Physicochemical analysis techniques, including X-ray phase analysis and electron probe X-ray analysis were employed in constructing the isothermal section of the Dy-Sb-Si system at 1100 K. The ternary intermetallic phases Dy₅₅Sb₁₆Si₂₈ [a=0.7746(3) nm, b=1.4853(5) nm, c=0.7761(3) nm], Dy₅₅Sb₃₁Si₁₃ [a=0.7802(3) nm, 1.4972(4) nm, c=0.7817(2) nm] and Gd₅₅Sb₁₅Si₂₉ [a=0.7892(5) nm, b=1.5128(7) nm, c=0.7925(5) nm] crystallize in the orthorhombic Sm₅Ge₄-type structure (space group Pnma; no. 62). Gd₆₂Sb₂₀Si₁₈ [a=0.8759(2) nm, c=0.6363(1) nm] crystallizes in the hexagonal Mn₅Si₃-type structure (space group P6₃/mcm; no. 193).

Full text of DOI:10.1016/S0925-8388(03)00080-X

Journal of Alloys and Compounds 358 (2003) L6–L8
L
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Letter
Dy–Sb–Si system at 1100 K and ternary intermetallic phases in the
Dy–Sb–Si and Gd–Sb–Si systems
*
A.V. Morozkin
Department of Chemistry, Moscow State University, Leninskie Gory, House 1, Building 3, Moscow, GSP-2, 119992, Russia
Received 8 January 2003; accepted 10 January 2003
Abstract
Physicochemical analysis techniques, including X-ray phase analysis and electron probe X-ray analysis were employed in constructing
the isothermal section of the Dy–Sb–Si system at 1100 K. The ternary intermetallic phases Dy55Sb16Si28 [a50.7746(3) nm,
b51.4853(5) nm, c50.7761(3) nm], Dy55Sb31Si13 [a50.7802(3) nm, 1.4972(4) nm, c50.7817(2) nm] and Gd55Sb15Si29 [a50.7892(5)
nm, b51.5128(7) nm, c50.7925(5) nm] crystallize in the orthorhombic Sm5Ge4-type structure (space group Pnma; no. 62).
Gd62Sb20Si18 [a50.8759(2) nm, c50.6363(1) nm] crystallizes in the hexagonal Mn5Si3-type structure (space group P63 /mcm; no. 193).
2003 Elsevier B.V. All rights reserved.
Keywords: Rare earth compounds; Crystal structure; Phase diagram; X-ray diffraction
X-ray analysis. X-ray data were obtained on a Dron-3.0
diffractometer (CuKa radiation, 2u520–708, step 0.058,
for 5 s per step). The diffractograms obtained were
The interaction between the components in the Sb–Si,
Dy–Sb and Dy–Si binary system has been studied in detail
in Refs. [1–3] (Table 1).
The present study was carried out on about 12 alloys
(Fig. 1). The alloys were made in an electric arc furnace
under an argon atmosphere using a nonconsumable tung-
sten electrode and a water-cooled copper tray. Silicon,
antimony, gadolinium and dysprosium (purity of each
component $99.99%) were used as starting components.
Titanium was used as a getter during the melting process.
The alloys were remelted twice in order to achieve
complete fusion and homogeneous composition. The
melted alloys were subjected to an anneal in evacuated
quartz ampoules containing titanium chips as a getter. The
ampoules were placed in a resistance furnace. The alloys
were annealed at 1100 K for 2 weeks. The samples were
quenched from 1100 K in ice-cold water.
The phase equilibria in the Dy–Sb–Si system were
determined using X-ray phase analysis and electron probe
*
Fax: 17-95-932-8846.
Fig. 1. Composition of samples investigated in the Dy–Sb–Si system.
E-mail address: morozkin@general.chem.msu.ru (A.V. Morozkin).
0925-8388/03/$ – see front matter
doi:10.1016/S0925-8388(03)00080-X
2003 Elsevier B.V. All rights reserved.

A.V. Morozkin / Journal of Alloys and Compounds 358 (2003) L6–L8
L7
Table 1
Crystallographic data of compounds in the binary Dy–Si and Dy–Sb systems. The R factors are given in percent (RF 5 100 ? (Sku(Ikobs
Sku(Iokbs
intensity calculated from refined structural parameters
)
1 / 2 2 (Ickal
)
1 / 2u)/
)
1 / 2u)%, Ikobs is the integrated intensity evaluated from summation of contribution of the kth peaks to net observed intensity, Ickal is the integrated
N
Compound
Space
group
Structure
type
a
(nm)
b
(nm)
c
RF
(%)
Refs.
(nm)
1
Sia
Sia
Fd3m
Fd3m
C
C
0.54307
0.5426(2)
[1]
b
3.8
2
3
Sb (LT)
Sb (HT)
R3m
P63 /mmc
As
Mg
0.43084
0.3369
1.1247
0.533
[1]
[1]
Dy (LT1)
Dy (LT2)a
Dy (HT)
Cmcm
P63 /mmc
Im3m
0.3595
0.35903
0.398
0.6183
1.448
0.5677
0.56475
[1]
[1]
[1]
Mg
W
4
Dy5Sia3
Dy5Sia3
P63 /mcm
P63 /mcm
Mn5Si3
Mn5Si3
0.837
0.856(1)
0.626
0.6046(7)
[1]
b
3.7
5
6
Dy5Sia4
Pnma
Sm5Ge4
0.736
0.765
[1]
DySi (HT)a
DySi (HT)a
DySi (LT)
Pnma
Pnma
Cmcm
FeB
FeB
CrB
0.787
0.7866(5)
0.4237
0.380
0.3816(2)
1.0494
0.565
0.5655(5)
0.3818
[1]
b
3.9
3.5
[1]
7
8
DySia1.67
DySia1.67
P6/mmm
P6/mmm
AlB2
AlB2
0.383
0.384(1)
0.411
0.415(1)
[1]
b
DySi2 (HT)
DySi2 (LT)a
DySi2 (LT)a
I41 /amd
Imma
Imma
ThSi2
GdSi2
GdSi2
0.403
0.404
0.4033(1)
1.338
1.334
1.3312(4)
[1]
0.394
0.3933(1)
[1]
b
3.4
5.0
9
DySba
DySba
Fm3m
Fm3m
NaCl
NaCl
0.61316
0.6142(4)
[1]
b
10
11
Dy4Sb3
I43d
Th3P4
0.9114
[1]
Dy5Sba3
Dy5Sba3
P63 /mcm
P63 /mcm
Mn5Si3
Mn5Si3
0.887
0.8886(9)
0.6266
0.6143(5)
[1]
b
3.8
a Compounds belong to the isothermal cross-section at 1100 K.
b Data for compounds from X-ray phase analysis of the three-component samples.
identified by means of calculated patterns using the RIETAN
program [4,5] in the isotropic approximation. A Camebax
microanalyser was employed to perform local X-ray
spectral analyses of the samples.
The results obtained were used in the construction of the
isothermal section of the Dy–Sb–Si system at 1100 K,
presented in Fig. 2.
The ternary intermetallic phases Sm5Ge4-type
Dy55Sb16Si28, Dy55Sb31Si13 and Gd5 5Sb15Si29 were found
in the Dy–Sb–Si and Gd–Sb–Si systems at 1100 K (Table
2).
It is obvious that the Dy55Sb16Si28 and Gd5 5Sb15Si29
compounds belong to extended regions of solid solutions
of the Sm5Ge4-type Dy5Si4 and Gd5Si4 compounds. The
Sm5Ge4-type Dy55Sb31Si13 compound is a ternary com-
pound. We have detected a Mn5Si3-type Gd62Sb20Si18
solid solution in the Gd–Sb–Si system. Dy5Si3 and the
other binary compounds of the Dy–Sb–Si system do not
show any visible solubility.
No Th3P4-type Dy4Sb3 compound was detected in the
Dy–Sb–Si system at 1100 K.
Fig. 2. Isothermal section of the Dy–Sb–Si system at 1100 K.

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A.V. Morozkin / Journal of Alloys and Compounds 358 (2003) L6–L8
Table 2
Crystallographic data of ternary phases in the Dy–Sb–Si and Gd–Sb–Si systems. The R factors are given in percent (RF 5 100 ? (Sku(Ikobs
)
1 / 2 2 (Ickal
)
1 / 2u)/
Sku(Iokbs
)
1 / 2u)%, Ikobs is the integrated intensity evaluated from summation of contribution of the kth peaks to net observed intensity, Ickal is the integrated
intensity calculated from refined structural parameters
N
Compound
Space
group
Structure
type
a
(nm)
b
(nm)
c
RF
(%)
(nm)
1
2
3
4
Dy55Sb16Si28
Dy55Sb31Si13
Gd5 5Sb15Si29
Gd62Sb20Si18
Pnma
Pnma
Pnma
P63 /mcm
Sm5Ge4
Sm5Ge4
Sm5Ge4
Mn5Si3
0.7746(3)
0.7802(3)
0.7892(5)
0.8759(2)
1.4853(5)
1.4972(4)
1.5128(7)
0.7761(3)
0.7817(2)
0.7925(5)
0.6363(1)
3.9
3.9
2.4
3.1
[3] G.V. Nikitina, V.N. Romanenko, P.N. Ishutina, Izv. AN SSSR,
Neorganich. Mater. 7 (1) (1971) 45–49, (In Russian).
[4] F. Izumi, Rigaku J. 6 (1) (1989) 10–19.
[5] F. Izumi, in: R.A. Young (Ed.), The Rietveld Method, Oxford
University Press, Oxford, 1993, Chapter 13.
References
[1] Person’s Handbook of Crystallographic Data for Intermetallic
Phases,Vol. 3, American Society for Metals, Metals Park, OH, 1985.
[2] K.E. Mironov, M.N. Abdusaliamova, O.R. Burnashev, Izv. AN
SSSR, Neorganich. Mater. 16 (11) (1980) 1951–1956, (In Russian).