Polyassociative thermodynamical model of A²B⁶ semiconductor melt and phase equilibrium in Cd-Hg-Te system: 3. Optimization of the thermodynamical functions of the model and quasi-binary structural diagram of Cd-Hg-Te system
Within the frames of the model of the polyassociative solutions the comparative analysis was performed of the formation parameters of multi-atom complexes in CdTe and Hg-Te systems. It was shown, that thermodynamical properties of the studied systems can be described in the supposition of the presen...
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| Опубліковано в: : | Semiconductor Physics Quantum Electronics & Optoelectronics |
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| Дата: | 2005 |
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Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України
2005
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| Цитувати: | Polyassociative thermodynamical model of A²B⁶ semiconductor melt and phase equilibrium in Cd-Hg-Te system: 3. Optimization of the thermodynamical functions of the model and quasi-binary structural diagram of Cd-Hg-Te system / Moskvin P.P., Rashkovetskiy L.V., Stronski A.V. // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2005. — Т. 8, № 2. — С. 81-85. — Бібліогр.: 12 назв. — англ. |
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Moskvin, P.P. Rashkovetskiy, L.V. Stronski, A.V. 2017-06-15T03:59:50Z 2017-06-15T03:59:50Z 2005 Polyassociative thermodynamical model of A²B⁶ semiconductor melt and phase equilibrium in Cd-Hg-Te system: 3. Optimization of the thermodynamical functions of the model and quasi-binary structural diagram of Cd-Hg-Te system / Moskvin P.P., Rashkovetskiy L.V., Stronski A.V. // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2005. — Т. 8, № 2. — С. 81-85. — Бібліогр.: 12 назв. — англ. 1560-8034 PACS: 64.90.+b https://nasplib.isofts.kiev.ua/handle/123456789/121650 Within the frames of the model of the polyassociative solutions the comparative analysis was performed of the formation parameters of multi-atom complexes in CdTe and Hg-Te systems. It was shown, that thermodynamical properties of the studied systems can be described in the supposition of the presence in the liquid phase of the ATe, A₂Te₃, ATe₂, A₂Te (A = Cd, Hg) and free Te, Cd, Hg atoms. In accordance with the model of polyassociative solutions the data on p–T–x equilibrium in the region of quasi-binary cross-section of Cd-Hg-Te system structural diagram were obtained. It was shown, that the mixing effects in the three-component liquid phase are satisfactorily described by the formation of CdHgTe and CdHgTe₃ associates. The good correspondence of the calculations and experiment in the high temperature part of the Cd-Hg-Te system structural diagram was achieved. en Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України Semiconductor Physics Quantum Electronics & Optoelectronics Polyassociative thermodynamical model of A²B⁶ semiconductor melt and phase equilibrium in Cd-Hg-Te system: 3. Optimization of the thermodynamical functions of the model and quasi-binary structural diagram of Cd-Hg-Te system Article published earlier |
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| title |
Polyassociative thermodynamical model of A²B⁶ semiconductor melt and phase equilibrium in Cd-Hg-Te system: 3. Optimization of the thermodynamical functions of the model and quasi-binary structural diagram of Cd-Hg-Te system |
| spellingShingle |
Polyassociative thermodynamical model of A²B⁶ semiconductor melt and phase equilibrium in Cd-Hg-Te system: 3. Optimization of the thermodynamical functions of the model and quasi-binary structural diagram of Cd-Hg-Te system Moskvin, P.P. Rashkovetskiy, L.V. Stronski, A.V. |
| title_short |
Polyassociative thermodynamical model of A²B⁶ semiconductor melt and phase equilibrium in Cd-Hg-Te system: 3. Optimization of the thermodynamical functions of the model and quasi-binary structural diagram of Cd-Hg-Te system |
| title_full |
Polyassociative thermodynamical model of A²B⁶ semiconductor melt and phase equilibrium in Cd-Hg-Te system: 3. Optimization of the thermodynamical functions of the model and quasi-binary structural diagram of Cd-Hg-Te system |
| title_fullStr |
Polyassociative thermodynamical model of A²B⁶ semiconductor melt and phase equilibrium in Cd-Hg-Te system: 3. Optimization of the thermodynamical functions of the model and quasi-binary structural diagram of Cd-Hg-Te system |
| title_full_unstemmed |
Polyassociative thermodynamical model of A²B⁶ semiconductor melt and phase equilibrium in Cd-Hg-Te system: 3. Optimization of the thermodynamical functions of the model and quasi-binary structural diagram of Cd-Hg-Te system |
| title_sort |
polyassociative thermodynamical model of a²b⁶ semiconductor melt and phase equilibrium in cd-hg-te system: 3. optimization of the thermodynamical functions of the model and quasi-binary structural diagram of cd-hg-te system |
| author |
Moskvin, P.P. Rashkovetskiy, L.V. Stronski, A.V. |
| author_facet |
Moskvin, P.P. Rashkovetskiy, L.V. Stronski, A.V. |
| publishDate |
2005 |
| language |
English |
| container_title |
Semiconductor Physics Quantum Electronics & Optoelectronics |
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Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України |
| format |
Article |
| description |
Within the frames of the model of the polyassociative solutions the comparative analysis was performed of the formation parameters of multi-atom complexes in CdTe and Hg-Te systems. It was shown, that thermodynamical properties of the studied systems can be described in the supposition of the presence in the liquid phase of the ATe, A₂Te₃, ATe₂, A₂Te (A = Cd, Hg) and free Te, Cd, Hg atoms. In accordance with the model of polyassociative solutions the data on p–T–x equilibrium in the region of quasi-binary cross-section of Cd-Hg-Te system structural diagram were obtained. It was shown, that the mixing effects in the three-component liquid phase are satisfactorily described by the formation of CdHgTe and CdHgTe₃ associates. The good correspondence of the calculations and experiment in the high temperature part of the Cd-Hg-Te system structural diagram was achieved.
|
| issn |
1560-8034 |
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https://nasplib.isofts.kiev.ua/handle/123456789/121650 |
| citation_txt |
Polyassociative thermodynamical model of A²B⁶ semiconductor melt and phase equilibrium in Cd-Hg-Te system: 3. Optimization of the thermodynamical functions of the model and quasi-binary structural diagram of Cd-Hg-Te system / Moskvin P.P., Rashkovetskiy L.V., Stronski A.V. // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2005. — Т. 8, № 2. — С. 81-85. — Бібліогр.: 12 назв. — англ. |
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2025-11-25T20:35:29Z |
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Semiconductor Physics, Quantum Electronics & Optoelectronics, 2005. V. 8, N 2. P. 81-85.
© 2005, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
81
PACS: 64.90.+b
Polyassociative thermodynamical model of A2B6 semiconductor melt
and phase equilibrium in Cd-Hg-Te system:
3. Optimization of the thermodynamical functions of the model and
quasi-binary structural diagram of Cd-Hg-Te system
P.P. Moskvin1, L.V. Rashkovetskiy2, A.V. Stronski2
1Zhitomir State Technological University, 103, Chernyakhovskiy Str., 10005 Zhitomir, Ukraine
E-mail:moskvin@us.ziet.zhitomir.ua
2V. Lashkaryov Institute of Semiconductor Physics, NAS of Ukraine, 41, prospect Nauky,
03028 Kyiv, Ukraine
Abstract. Within the frames of the model of the polyassociative solutions the
comparative analysis was performed of the formation parameters of multi-atom
complexes in CdTe and Hg-Te systems. It was shown, that thermodynamical properties
of the studied systems can be described in the supposition of the presence in the liquid
phase of the ATe, A2Te3, ATe2, A2Te (A = Cd, Hg) and free Te, Cd, Hg atoms. In
accordance with the model of polyassociative solutions the data on p–T–x equilibrium in
the region of quasi-binary cross-section of Cd-Hg-Te system structural diagram were
obtained. It was shown, that the mixing effects in the three-component liquid phase are
satisfactorily described by the formation of CdHgTe and CdHgTe3 associates. The good
correspondence of the calculations and experiment in the high temperature part of the
Cd-Hg-Te system structural diagram was achieved.
Keywords: phase equilibrium, polyassociative model.
Manuscript received 21.01.05; accepted for publication 18.05.05.
In our previous works [1, 2] it was shown, that the
polyassociative model of the melt can be successfully
applied for the description of the phase equilibrium in
binary 62BA systems. In this work the obtained
thermodynamical information on the thermodynamical
properties of the initial binary components of
TeHgCd x1x − solid solution will be disseminated on the
analysis of the structural diagram of ternary Cd-Hg-Te
system.
Before the analysis of the interphase interaction in
ternary system it is necessary to make some gene-
ralizations on the thermodynamical behavior of Hg-Te
and Cd-Te systems within the frame of the model of
polyassociative solutions. Mentioned above at first
place refers to the melts associative composition of this
related systems. According to the calculations [1], Hg-
Te melt energetic state can be modeled under its
consideration as consisting from the next complexes:
HgTe, 22 Te,HgTe . At the same time Cd-Te liquid
phase, which provide satisfactory description of the
phase equilibrium in system must consist of the
following associates: CdTe, Cd2Te, Cd2Te3, CdTe2, Te2
and free Cd and Te atoms. The increase of the number
of associates in liquid Cd-Te phase is connected with the
necessity to describe the liquidus of a system, the form
of which is more complex than in Hg-Te system. The
use in the calculations more simple representations about
associative structure if mercury containing melt system
nevertheless founds its reflection in lesser accuracy in
the description of the liquidus of system, especially at
XTe values in the interval of 0.5 to 0.6 atomic parts
(Fig. 1 from [1]).
The calculations of phase diagram in Hg-Te system
show that the accuracy increase in the liquidus
description is possible by introduction into consideration
of the complex with 32TeHg composition. This
associate in the highest concentration must be present in
the melt with composition, which correspond to the most
favorable conditions of its creation, that is at 3/5Te =X
atomic parts. As was already mentioned, exactly in this
interval the biggest differences in calculated and
experimental data on the liquidus of the system are
observed. Taking into account the mentioned facts, as
well as considerations of the generality of the state
description of 62BA liquid phase system, it is necessary
to correct thermodynamical model of Hg-Te melt and to
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2005. V. 8, N 2. P. 81-85.
© 2005, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
82
Fig. 1. Quasi-binary cross-section of the structural diagram of
Cd-Hg-Te system. +, ×, ο, ٱ − experimental data [8, 9, 10, 11].
introduce onto it the associate of 32TeHg type.
Naturally this will require the reevaluation of the
functional dependencies of dissociation constants on the
temperature for all complexes which are present in liquid
phase. Let us note that 32TeHg associate was initially
was introduced in [3] during description of the
mentioned above system dependence of the melt mole
volume on its composition. Thus the such type
correction of model considerations of Hg-Te melt
associative structure can be considered as consistent and
non-contradictive.
One of the perspectives of polyassociative solutions
model application to the description of phase
equilibrium was connected with the decrease of the
thermodynamical parameters number, the experimental
evaluation of which is difficult or simply impossible [1].
In this respect it seems reasonable to evaluate the
possibility of minimization of model parameters number
at the cost of the lowering of the number of considered
associates in liquid phase. In present work such attempt
was performed in relation to the 2Te associate. This
possibility appears if temperature dependence of the
dissociation complex for complexes of 32TeA type is
considered in more complex form. Such approach
enabled to exclude the two-atomic complex of tellurium
from the model. For the compensation of its influence on
the liquidus behavior the temperature dependencies of
type )exp( 2T
C
T
BAK mn ++= were used for dissociation
parameters of 32TeA , 2ATe . The performed
reevaluation of dissociation parameters, at first place
refers to the description of the enriched by tellurium part
of structural diagram of the system. At the same time for
the generality of the thermodynamical analysis it
considered necessary to perform additional analysis of
the associative structure of liquid phase enriched by
metallic components. Mentioned above refers to the
presence of TeA2 complex, which influence the shape
of liquidus only in the enriched by metal part of the
structural diagram. Indeed, it was necessary in the
calculations of the liquidus of Cd-Te system in the
neighborhood of the bend point of equilibrium line for
the tellurium content in the melt about 0.3 atomic parts.
Liquidus of Hg-Te system, in its part enriched by
mercury, does not have such peculiarity, its shape is
sufficiently traditional (degenerate in comparison to the
structural diagram of Cd-Te system), does not have bend
points, and is satisfactory described with taking into
account only HgTe associate. It seems, that there is no
reasons for introduction into analysis of more complex
enriched by metal TeHg2 complex. But such complex
is considered necessary for the precise description of
liquidus at temperatures lower than 500 К, that is at
temperatures typical for the carrying out of the epitaxial
growth from the enriched by metals melt. Taking into
account mentioned above considerations the decision
was made to introduce to the equations of phase
equilibrium the component which takes into account the
creation of the TeHg2 associate. Quasi-chemical
equation of its formation is analogous to the equation of
TeCd2 complex formation [2]. Concluding the
discussion of the associative structure of Cd-Te and
TeHg − melts, it is seemed necessary to mention the
following. Calculations show, that despite the
insignificant content of associates of complex
composition in liquid phase, their concentration
essentially influence partial concentration of
components. Thus, even if their influence on the shape
of liquidus of the systems is small, disregarding their
contribution to the value of equilibrium pressures leads
to the substantial differences of theory and experiment.
This is an important argument to take them into account
during modeling of the thermodynamical state of the
liquid phase.
The reliability of the theoretical analysis of the phase
equilibrium in Cd-Hg-Te system is determined by the
final choice of the entropy value of HgTe melting. Let
us remind, that the increase of this parameter from 9.25
up 14 e.u. during description of the XTp −−
equilibrium in the mentioned system enabled to achieve
good correspondence of the calculations to the
experiment in [1]. The analysis of the phase equilibrium
in the related Cd-Te system has shown, that variations of
such type are not necessary for the description of the
pressure of the metallic component in this system.
Proceeding from the generality of the analysis of the
structural diagram in the 62BA , it was decided in the
consequent calculations to leave the value
e.u.0.14HgTe =Δ FS unchanged and corresponding to the
experimental data [4], despite the decrease of the
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2005. V. 8, N 2. P. 81-85.
© 2005, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
83
accuracy in the description of mercury pressure in the
system [1].
Such reevaluation of the temperature dependencies
of dissociation constants in Hg-Te systems, when in the
melt 32TeHg , TeHg2 complexes are present was
performed in the present work. The method of the search
of these functions is similar to the procedure described
in [1]. The corrected values of the thermodynamical
parameters of Hg-Te melt were the following:
)/5591249.76exp((HgTe) TK += ;
)10359.110641.5249.76exp()Te(Hg
5
2
7
32 TT
K −+= ;
)10004.810809.2987.53exp()(HgTe
5
2
7
2 TT
K −+= ;
6.0Te)(Hg2 =K .
Similar correction of the thermodynamical functions
of the complex dissociation was performed also for the
description of the state of Cd-Te liquid phase. As
previously, in order to decrease the number of
thermodynamical parameters 2Te complex was exclu-
ded. With such correction temperature dependencies of
the dissociation constants provide satisfactory
description xTp −− equilibrium in Cd-Te system and
are presented by:
)10289.210554.1245.78exp((CdTe)
5
2
8
TT
K −+= ;
)10828.110314.756.5exp()(CdTe
4
2
6
2 TT
K −+= ;
)1012.310817.1511.120exp()Te(Cd
5
2
8
32 TT
K −+= ;
02.0Te)(Cd 2 =K .
In the consequent calculations structural diagrams of
the ternary Cd-Hg-Te system the latter from the found
thermodynamical functions were applied during
description of the phenomena of the corresponding
complexes in the liquid phase.
The presence of the two metallic components of the
melt in Cd-Hg-Te liquid phase supposes the appearance
of the specific, characteristic for the ternary system types
of the associates. Following tested on the binary systems
associative composition of the melt, and in the
approximation when in the melt only multicomponent
complexes with two metal atoms of 32BA and
BA2 type exist, it is possible to suppose, that in the
considered ternary component melt the 3CdHgTe and
CdHgTe associates must be present. Such complexes
must be responsible for the description of the mixing
phenomenon between metal components of the liquid
phase. According to the method of quasi-chemical
reactions it is possible to write:
33 CdHgTe
3
TeHgCdCdHgTe /)( xxxxTK ⋅⋅= , (1)
CdHgTeTeHgCdCdHgTe /)( xxxxTK ⋅⋅= ,
where 3CdHgTex and CdHgTex – concentrations of
3CdHgTe and CdHgTe complexes in melt;
)(
3CdHgTe TK and −)(CdHgTe TK dissociation constants
of complexes. In the last expression, as earlier, during
record of the reaction of the mentioned complex
formation the preference was given to its creation from
the free atoms.
During transfer to the description of the state of
ternary liquid phase the equations of the balance of the
matter in the melt under presence of all of the mentioned
above complexes and with taking into account of the
3CdHgTe and CdHgTe particles can be written as:
;0
-)(2
CdCdHgTeCdHgTe
TeCdTeCdCdTeCdTeCd
3
2322
=−−−
+−−−
xxx
xxxxGX
;0
-)(2
HgCdHgTeCdHgTe
TeHgTeHgHgTeHgTeHg
3
2322
=−−−
+−−−
xxx
xxxxGX
;0)
(3
)(2
TeCdHgTe
TeCdTeHgTeCdTeHg
CdTeHgTeCdHgTeCdTeHgTeTe
3
323222
22
=−+
++−−−
−+−−−−
xx
xxxx
xxxxxGX
; )4(
)
(21
33232
22
22
CdHgTeTeHgTeCd
CdHgTeTeHgTeCd
HgTeCdTeHgTeCdTe
xxx
xxx
xxxxG
+++
++++
+++++=
1CdHgTe =++ XXX ; ,1
13
1
=∑
=i
ix (2)
where HgX , TeX , CdX – atomic parts of mercury,
tellurium, cadmium in melts,
qp
x TeHg ,
qp
x TeCd – mol.
parts of complexes of qpTeHg and qpTeCd
composition in liquid phase.
Presented formula are consequence of equations
which describe interconnection of the mole number for
each complex with the atomic and mole part of the
components of the melt. Thus in corrected model the
Cd-Hg-Te melts consists from following associates:
HgTe, Hg2Te, HgTe2, Hg2Te3, CdTe, Cd2Te, Cd2Te3,
CdTe2, CdHgTe3, CdHgTe and free TeHg,Cd, atoms.
General number of the particles in the melt is 13.
Within the frames of the accepted model the pressure
of the melt components is connected with the
concentration of the non-associated cadmium, mercury
and tellurium atoms and is calculated according to the
Raoult-Henry law using following formula [1, 2]:
;Cd
o
CdCd xpp ⋅= ;Hg
o
HgHg xpp ⋅= ;2
Te
o
TeTe 22
xpp ⋅=
where ix , o
ip - atomic parts of free cadmium, mercury
and tellurium, and also partial pressures of the
mentioned components over their melts. Partial
pressures of all components over own melt which were
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2005. V. 8, N 2. P. 81-85.
© 2005, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
84
used in calculations are presented with the respective
references in [1, 2].
The equations of the heterophase equilibrium
between ternary liquid and solid phases according to the
theory of regular solutions and approximation of poly-
associative structure of the melt are given by [1, 2, 5]:
;ln)ln(/)( CdTeCdTeSl
Te
Sl
Cd
TeCd
CdTeCdTe
SFF x
xx
xx
RTTTS γ=
⋅
⋅
+−Δ
;ln)ln(/)( HgTeHgTeSl
Te
Sl
Hg
TeHg
HgTeHgTe
SFF x
xx
xx
RTTTS γ=
⋅
⋅
+−Δ
);1(ln S
j
S
j xRT −=⋅ αγ ;HgTeCdTe,=j
,1CdTeHgTe =+ SS xx (3)
where F
j
F
j TS ,Δ – entropies and melting temperatures
of the initial substances; jγ – activity coefficient of the j
component in solid phase; index Sl refers to the liquid
phase of stoichiometric composition. According to data
from [1, 2]: at.pt.0435.0Sl
Cd =x , at.pt.0494.0Sl
Te =x ( for
Cd-Te system); at.pt.2903.0Sl
Hg =x ; at.pt.252.0Sl
Te =x
(for Hg-Te system ).
For modeling of the solid state phase and calculation
of the phase diagram the quantitative information about
parameter of the solid phase interaction Sα between
cadmium and mercury in the metallic sublattice of solid
solution. This parameter, as well as
3CdHgTeK , CdHgTeK
parameters, is necessary to consider as matching, which
are determined according to the best correspondence of
the calculations on xTp −− equilibrium to the
experiment in the ternary system.
The search of the unknown thermodynamical
functions began with the treatment of the experimental
data on phase equilibrium in the region of quasi-binary
cross-section of structural diagram of the system. For
this part of the diagram reliable and spacious data on the
liquidus and solidus of the system are available [8-11]
and several experimental results on the pressure of
components vapor results over the melt [11]. At the first
stage of the analysis it was supposed, that the
phenomena of mixture between Cd and Hg it is
possible to describe by the formation of the complex of
3CdHgTe composition. As the base for such supposition
served the fact, that exactly complexes of 32BA type
are most numerous together with AB , in the
neighborhood of the melting temperature of the initial
binary components of the system. But calculation have
shown, that, even under the substantial variation of the
value of the mentioned complex dissociation parameter,
to describe the liquidus of the system, even nearing to
the experimental data, is impossible. Such result means,
that complex of 3CdHgTe composition can not be the
only one associate responsible for the effects of
components mixing in the ternary melt.
Other situation was observed during consideration of
CdHgTe complex. In this case the calculated curve of
liquidus is the neighborhood of the experiments, when
4
CdHgTe 104 −⋅≈K . Under that the maximal
concentration of the mentioned complex was not bigger
than 0.25 mol. pt. For the description of the behavior of
the systems solidus, as the first approximation was
chosen the ideal assumption for the description of the
solid phase components of the melt, that is the values of
the Sα parameter in Eq. (3) was varied in the
neighborhood of zero. Such range of the searched
parameter change does not contradict the data from the
milestone works [6, 7] and is seen acceptable from the
theoretical positions of the regular solutions model [12].
Indeed, insignificant difference in the periods of the
crystalline lattice of initial mixing components ( CdTe
and HgTe ) supposes small contribution of the elastic
component of the mixing energy into total energy of
solid state. It is known, that exactly this component
gives main contribution to the excess energy of the
components mixing in solid phase [12]. Preliminary
calculations with the mentioned parameters has shown,
that high temperature part of the diagram is quite
adequately described by the regular approximation for
the solid phase with Sα parameter insignificantly
deviating from zero. At the same time the effects of the
mixing of the melt metallic components must be
described at first place, by associate of
CdHgTe composition, also the use in the analysis of the
3CdHgTe complex also enables to control the liquidus
of the quasi-binary cross-section near HgTe .
The calculation results has shown, that satisfactory
description of the equilibrium lines at temperatures of
quasi-binary cross-section is achieved under the following
values of the searched parameters: αS ≈ −1500 cal./mol.;
4
CdHgTe 103 −⋅≈K and 3
CdHgTe 105
3
−⋅≈K .
In Fig. 1 the calculation results for the quasi-binary
structural of the diagram Cd-Hg-Te system with the
respective experimental data are presented [8-11]. The
good correspondence of the calculations with the
experimental results on the liquidus and solidus of the
system are presented. In Fig. 2 jointly with the
experiments from paper [9] the data on the components
pressure over the melt along the quasi-binary cross
section are presented. Taking into account the small
accuracy of the components pressure at high
temperatures, the correspondence of the calculations to
the experiment also in this situation can be considered
satisfactory.
In Fig. 3, the concentrations of the main associates in
the melt along liquidus line along the considered cross-
section are presented. It is seen from the figure, that the
behavior of the equilibrium line mainly is determined by
the HgTe, CdTe, Hg2Te3, Cd2Te3, CdHgTe, CdHgTe3
complexes content in the melt. It is necessary to note,
Semiconductor Physics, Quantum Electronics & Optoelectronics, 2005. V. 8, N 2. P. 81-85.
© 2005, V. Lashkaryov Institute of Semiconductor Physics, National Academy of Sciences of Ukraine
85
Fig. 3. Content of prevailing associates in the melt along quasi-
binary cross-section of the structural diagram of Cd-Hg-Te
system. 1 − Hg; 2 − Te; 3 − CdTe; 4 − HgTe; 5 − Cd2Te3; 6 −
CdHgTe; 7 − Hg2Te3; 8 − CdHgTe3; 9 − Hg2Te; 10 − CdTe2.
Fig. 2. Pressure of components along quasi-binary cross-
section of structural diagram of Cd-Hg-Te system. 1, 2, 3 –
refers to the pressure of mercury, cadmium and tellurium.
Experimental data [11].
that, content of the complexes which are responsible for
the effects of metallic components mixing, is enough
essential and commensurable with the associate con-
centration in the initial two-component phases. The last
one can be interpreted as the confirmation of the
substantial deviation of the mixed liquid components
behavior from the predicted by the model of the ideal
solutions,also the shape of the lines of the quasi-binary
cross-section is traditional. The last fact sometimes is
interpreted as testimony of the proximity of the systems
thermodynamical state to that one, described by the
model of ideal solutions. Such statement does not find its
justification by our analysis and calculations.
The final parameters search of the temperature de-
pendencies of the ternary associates dissociation cons-
tants and value of the parameter of solid phase interact-
tion will be performed in the next part of the work. As a
base for the consequent analysis will serve the data on
the low temperature fragments of structural diagram
(data on liquid phase epitaxy), as for the enriched by
metal part of the diagram as well for its tellurium part.
Thus, the results obtained enable to state, that the
model of the polyassociative solutions is capable to
satisfactory description of the phase equilibrium in the
region of the quasi-binary cross-section of the 62BA
ternary systems. Obtained in this work thermodynamical
functions of the dissociation of a melt components are
applicable for the description of the high-temperature
phase equilibrium in Cd-Hg-Te system.
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