Thermodynamics and phase diagram calculations in II-VI and IV-VI ternary systems using an associated solution model

Laugier, A.

doi:10.1051/rphysap:0197300803025900

Cited by 136 publications

(32 citation statements)

References 31 publications

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“…Subsequent thermal treatment was performed at 390 °C (663 K in Figure 1 b) for 336 h, under argon atmosphere, to ensure phase separation in the vicinity of the miscibility gap of the quasi-binary Pb 0.95 Sn 0.05 TePbS system (Figure 1 b). The phase diagram was constructed based on previously reported thermodynamic data of the PbTePbS [ 23,24 ] and PbTe-SnTe systems. [ 25,26 ] [ 1 ] b) Quasi-binary phase diagram of the PbTe-PbS system as previously reported [ 23 ] (black curve) and [ 24 ] (red curve), as well as of the Pb 0.95 Sn 0.05 Te-PbS system (blue curve), calculated for 100% Pb 0.95 Sn 0.05 Te from the quasi-binary PbTe-SnTe phase diagram [ 25 ] and intermediate compositions reported previously at 900, 1000, and 1200 K. [ 26 ] c) Confi guration of the analyzed segmented thermoelectric couple in this work, based on two n-type 0.055% and 0.01% PbI 2 (Figure 1 c) were prepared by simultaneously hot pressing of the two individual powder compositions under the same conditions applied for each of the compositions separately.…”

Section: Methodsmentioning

confidence: 99%

Functional Graded Germanium–Lead Chalcogenide‐Based Thermoelectric Module for Renewable Energy Applications

Hazan

Ben-Yehuda

Madar

et al. 2015

Advanced Energy Materials

103

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methods to enhance the materials' thermoelectric properties, practical design considerations including geometrical optimization and minimization of contact resistances and long-term properties degradation should be considered. For many years, thermoelectric power generation has enjoyed its greatest success in special and exotic applications, such as the space missions, in which the chalcogenides class of thermoelectric materials (e.g., GeTe, [1][2][3][4] PbTe, [5][6][7][8][9][10] PbS, [11][12][13][14] SnTe, [15][16][17][18][19][20][21] or their alloys) is the most thermoelectrically effi cient in the intermediate temperature range of ≈500 °C, but still the system conversion effi ciency for a state-ofpractice NASA RTG (radioisotope thermoelectric generator) is about 6%, [ 22 ] where in this type of application environmental issues and cost are not the main concerns. In this thermoelectric materials class, it was recently reported that upon proper compositional investigation for systems exhibiting a miscibility gap between two individual chalcogenide components, sub-micron thermodynamic-driven phase separation features are expected, leading to dramatically reduced thermal conductivity values and enhanced ZT s. Two examples are the p-type Ge 0.87 Pb 0.13 Te, [ 1 ] shown in Figure 1 a, and the n-type 0.055% PbI 2 doped (PbSn 0.05 Te) 0.92 (PbS) 0.08 [ 11 ] compositions, exhibiting very high maximal ZT s of ≈2.2 and ≈1.5, respectively, and correspondingly a very high thermoelectric potential.For the latter, investigation of the PbS-PbTe quasi-binary phase diagram, Figure 1 b reveals an extended miscibility gap at temperatures below 800 °C (1073 K in Figure 1 b), in which a higher-temperature solution-treated single phase (the upper scanning electron microscopy, SEM image) is expected to follow a rapid phase separation to two individual PbTe-and PbS-rich phases (the lower SEM image) by either the spinodal decomposition or nucleation and growth mechanisms, upon cooling, depending on the specifi c composition. Due to the rapid nature of these phase separation reactions, the apparent alternating phases are usually fi nely dispersed, making them very useful phonon scattering centers for thermal conductivity reduction. Due to its thermodynamic origin, such a submicron phase generation is considered much more stable at elevated operating temperatures, compared to any other mechanical nano-features generation approaches such as ball-milling, which are expected to follow coarsening into the micron scale with long-term operations.

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Section: Methodsmentioning

confidence: 99%

Functional Graded Germanium–Lead Chalcogenide‐Based Thermoelectric Module for Renewable Energy Applications

Hazan

Ben-Yehuda

Madar

et al. 2015

Advanced Energy Materials

103

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“…Miller and Komarek [23] used resistivity measurements for the description of homogeneity range of PbTe intermetallic compound. Previous calculations of the Pb-Te binary system were done by Laugier [41], Laugier et al [42], Szapiro et al [28], Kharif et al [29] and Kattner et al [43]. Results obtained in previous works look well; however, taking into account capability of ionic liquid model for Tellurium base alloys modeling we decided to repeat optimization of the system.…”

Section: Literature Informationmentioning

confidence: 99%

Thermodynamic description of the Pb–Te system using ionic liquid model

Gierlotka

Łapsa

Jendrzejczyk-Handzlik

2009

Journal of Alloys and Compounds

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“…The positions (') and (") on the gm (k, /) face at which the activity coefficients are to be determined by numer ical derivation, are calculated for each iteration step by bicubic spline interpolation using the tabulated 0m ( M grid. (Table 2) was calculated by Laugier [14] from experimental data measured by Steininger [15] and Grimes [16].…”

Section: O N Fig U Ra Tio N E N Tro P Y Of a C Lu S Te R M Ix Tu Rementioning

confidence: 99%

Thermodynamic Excess Functions for Quasiternary Solid Solutions of Type M(X,Y,Z) I. The System Pb (S,Te,Se)

Leute

1995

Zeitschrift Für Naturforschung A

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Dedicated to Prof. Dr. W . Müller-Warmuth on the occasion of his 65th birthdayThe excess free enthalpy of quasiternary systems of type M (X, Y, Z) with two sublattices, a mixed one (X, Y,Z) and a pure one (M), will be described in two ways: (1) by the interaction parameters of the three subregularly treated quasibinary subsystems and by one ternary parameter, and (2) by the cluster energies of 10 pyramidal clusters.It is shown that, for the spinodal miscibility gap in the special system Pb (S, Te, Se), both versions yield satisfying accordance of experiments and calculated results. IntroductionIn several recent papers relationships between properties of a ternary system and its three binary subsystems were discussed on a phenomenological level [1,2,3], In this paper, we will use a microscopic cluster model based on four particle interactions, i.e. on interactions between one particle of the pure M-sublattice and three particles of the mixed XYZsublattice. Due to these pyramidal clusters our model can be applied to octahedrally, i.e. Pb(S,Te, Se), as well as to tetrahedrally coordinated quasiternary onephase systems, as for example to As(Al,Ga,In) or to Te(Zn, Cd, Hg).We will show that, for the case of random distribu tion within the mixed sublattice, the expression for the excess free enthalpy of the quasiternary solution can be splitted into contributions from the three subregu larly behaving quasibinary subsystems and an addi tional contribution described by a ternary interaction parameter. For an ideal cluster mixture, the standard chemical potentials of all but one cluster can be esti mated from the temperature dependent interaction parameters of the quasibinary subsystems. It is only the value for the "ternary" cluster MXYZ, with X / Y ^ Z, that has to be estimated from measure ments on ternary mixtures. Knowing all the cluster energies, the probabilities for the clusters can be calcu lated and then the configuration entropy of the cluster Reprint requests to Prof. V. Leute. mixture can be described as a function of the cluster probabilities. Thus, for an ideal cluster mixture the mean molar free mixing enthalpy can be calculated from the cluster energies.For the special system Pb(St Te,Sem ) we will calcu late the miscibility gap for spinodal demixing from the phenomenological expression as well as from the clus ter expression for the free mixing enthalpy. The inter action parameters needed for the calculations will be derived from data on the quasibinary subsystems.The scope of a description of a real mixture by a cluster model is not restricted to calculations of ther modynamic properties such as the excess free en thalpy. Moreover, such a description has the advan tage of an atomistic model. It allows to calculate the probability of special atomic arrangements, as for ex ample pairs of equal particles on adjacent lattice sites. Thus, one can illustrate by this model, for example, in which way the equilibria between clusters have to change with composition and temperature to favour demixing. Experiments ...

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Thermodynamics and phase diagram calculations in II-VI and IV-VI ternary systems using an associated solution model

Cited by 136 publications

References 31 publications

Functional Graded Germanium–Lead Chalcogenide‐Based Thermoelectric Module for Renewable Energy Applications

Functional Graded Germanium–Lead Chalcogenide‐Based Thermoelectric Module for Renewable Energy Applications

Thermodynamic description of the Pb–Te system using ionic liquid model

Thermodynamic Excess Functions for Quasiternary Solid Solutions of Type M(X,Y,Z) I. The System Pb (S,Te,Se)

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