Nanostructure and doping stimulated phase separation in high-ZT Mg2Si0.55Sn0.4Ge0.05 compounds

Polymeris, George S.; Vlachos, Nikolaos; Khan, Atta Ullah; Hatzikraniotis, Euripides; Lioutas, Ch. B.; Delimitis, A.; Pavlidou, E.; Paraskevopoulos, K. M.; Kyratsi, Theodora

doi:10.1016/j.actamat.2014.09.031

Cited by 43 publications

(26 citation statements)

References 34 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Experimental determination of ZT even in a single alloy exhibits considerable variance, perhaps due to changes in the way these materials are synthesized and processed. Recently, the present authors and collaborators investigated the effect of non-equilibrium processing on the microstructure evolution (and transport properties) in the Mg 2 Si 0.7 Sn 0.3 system and found that instead of phase-separating, the system tended to form a solidsolution with superior TE performance, contrary to expectations and prior works [56,65]. This was ascribed to (elastic) coherency effects and was verified via quantitative multi-physics phase field simulations [39].…”

Section: Nanostructured Thermoelectric Materialsmentioning

confidence: 63%

Uncertainty propagation in a multiscale CALPHAD-reinforced elastochemical phase-field model

et al. 2020

View full text Add to dashboard Cite

ICME approaches provide decision support for materials design by establishing quantitative process-structure-property relations. Confidence in the decision support, however, must be achieved by establishing uncertainty bounds in ICME model chains. The quantification and propagation of uncertainty in computational materials science, however, remains a rather unexplored aspect of computational materials science approaches. Moreover, traditional uncertainty propagation frameworks tend to be limited in cases with computationally expensive simulations. A rather common and important model chain is that of CALPHAD-based thermodynamic models of phase stability coupled to phase field models for microstructure evolution. Propagation of uncertainty in these cases is challenging not only due to the sheer computational cost of the simulations but also because of the high dimensionality of the input space. In this work, we present a framework for the quantification and propagation of uncertainty in a CALPHADbased elasto-chemical phase field model. We motivate our work by investigating the microstructure evolution in Mg 2 (Si x Sn 1−x ) thermoelectric materials. We first carry out a Markov Chain Monte Carlo-based inference of the CALPHAD model parameters for this pseudobinary system and then use advanced sampling schemes to propagate uncertainties across a high-dimensional simulation input space. Through high-throughput phase field simulations we generate 200,000 time series of synthetic microstructures and use machine learning approaches to understand the effects of propagated uncertainties on the microstructure landscape of the system under study. The microstructure dataset has been curated in the Open Phase-field Microstructure Database (OPMD), available at http://microstructures.net.

show abstract

Section: Nanostructured Thermoelectric Materialsmentioning

confidence: 63%

Uncertainty propagation in a multiscale CALPHAD-reinforced elastochemical phase-field model

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Please do not adjust margins Please do not adjust margins rotating chilled copper roller, quickly solidifying in the form of thin ribbons. Independently of the reaction method used, the fabrication of these materials is normally complemented by a densification step such as hot pressing 24,99,104 or spark plasma sintering 64,108,112 . The latter greatly reduces the duration of this step by promoting the sintering of particles through passage of an electrical current when pressure is applied, allowing for certain nanostructures to be maintained.…”

Section: Journal Of Materials Chemistrymentioning

confidence: 99%

“…These suggest that the miscibility gap is wider than what has been previously accepted, and the author concludes that reports on high zT thermoelectrics are likely not single-phase, questioning the stability of their thermoelectric properties in high temperature applications over an extended time. The discrepancy between reports on single-phase compounds and ab-initio phase stability calculations 115 has been reinforced in recent works on Mg 2 Si-Mg 2 Sn thermoelectric materials, where electron microscopy techniques were used to observe more than one phase in these compounds, which could not be completely resolved by X-ray analysis 60,104 .…”

Section: Solid Solutions and Phase Diagramsmentioning

confidence: 99%

Recent progress in magnesium-based thermoelectric materials

2018

View full text Add to dashboard Cite

show abstract

“…Therefore, according to the theory of alloying scattering [28][29][30] , the formation of nanoscale (e.g., formation of nanoparticles or nanoprecipitates) just as the case in Mg 2 Sn-Mg 2 Si-Mg 2 Ge system 22 . These nanostructures effectively scatter phonons to lower the lattice thermal conductivity [31][32][33][34][35] .…”

Section: Introductionmentioning

confidence: 99%

Thermoelectric performance enhancement of Mg₂Sn based solid solutions by band convergence and phonon scattering via Pb and Si/Ge substitution for Sn

Mao

Wang

et al. 2016

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

In this study, the thermoelectric properties of Mg2Sn0.98-xPbxSb0.02 were first studied, and then Mg2Sn0.93-xSixPb0.05Sb0.02 and Mg2Sn0.93-xGexPb0.05Sb0.02 were accordingly investigated. The results showed that the formation of Mg2Sn0.98-xPbxSb0.02 solid solutions effectively reduced the lattice thermal conductivity of Mg2Sn. The room temperature lattice thermal conductivity of Mg2Sn0.98Sb0.02 is ∼5.2 W m(-1) K(-1) but only ∼2.5 W m(-1) K(-1) for Mg2Sn0.73Pb0.25Sb0.02, a reduction of ∼52%. Further alloying Mg2Sn0.98-xPbxSb0.02 with Mg2Si or Mg2Ge to form Mg2Sn0.93-xSixPb0.05Sb0.02 or Mg2Sn0.93-xGexPb0.05Sb0.02 reduced the lattice thermal conductivity significantly due to enhanced phonon scattering by point defects as well as nanoparticles. Moreover, bipolar thermal conductivities were suppressed due to the larger bandgap of Mg2Si and Mg2Ge than Mg2Sn. Furthermore, similar to the pseudo-binary Mg2Sn-Mg2Si and Mg2Sn-Mg2Ge systems, band convergence was also observed in pseudo-ternary Mg2Sn0.93-xSixPb0.05Sb0.02 and Mg2Sn0.93-xGexPb0.05Sb0.02 materials. The convergence of conduction bands led to higher PFs at lower temperatures for Mg2Sn0.93-xSixPb0.05Sb0.02 and Mg2Sn0.93-xGexPb0.05Sb0.02 materials. As a result, higher peak ZTs of ∼1.3 for Mg2Sn0.63Si0.3Pb0.05Sb0.02 and ∼1.2 for Mg2Sn0.68Ge0.25Pb0.05Sb0.02 were achieved.

show abstract

Nanostructure and doping stimulated phase separation in high-ZT Mg2Si0.55Sn0.4Ge0.05 compounds

Cited by 43 publications

References 34 publications

Uncertainty propagation in a multiscale CALPHAD-reinforced elastochemical phase-field model

Uncertainty propagation in a multiscale CALPHAD-reinforced elastochemical phase-field model

Recent progress in magnesium-based thermoelectric materials

Thermoelectric performance enhancement of Mg₂Sn based solid solutions by band convergence and phonon scattering via Pb and Si/Ge substitution for Sn

Contact Info

Product

Resources

About

Nanostructure and doping stimulated phase separation in high-ZT Mg2Si0.55Sn0.4Ge0.05 compounds

Cited by 43 publications

References 34 publications

Uncertainty propagation in a multiscale CALPHAD-reinforced elastochemical phase-field model

Uncertainty propagation in a multiscale CALPHAD-reinforced elastochemical phase-field model

Recent progress in magnesium-based thermoelectric materials

Thermoelectric performance enhancement of Mg2Sn based solid solutions by band convergence and phonon scattering via Pb and Si/Ge substitution for Sn

Contact Info

Product

Resources

About

Thermoelectric performance enhancement of Mg₂Sn based solid solutions by band convergence and phonon scattering via Pb and Si/Ge substitution for Sn