A Review of the Mg2(Si,Sn) Alloy System as Emerging Thermoelectric Material: Experimental and Modeling Aspects

Perturbation theory and thermal transport in mass-disordered alloys: Insights from Green's function methods

“…3 Ω Tr [ImG S ImG S] can be defined as the phonon transport distribution function (TDF) Σ ph (ω), in analogy with the case of thermoelectric transport (see equation (11) in Ref. 48, where −∂f 0 /∂ is the normalized window in the electronic case).…”

“…In terms of thermal management applications, a variety of novel alloys have been developed and employed, particularly towards reducing vibrational contributions to thermal transport for more efficient thermoelectrics -example alloys include Si 1−x Ge x [8], PbTe 1−x Se x [9], half-Heusler alloys [10], and Mg 2 Si 1−x Sn x [11,12]. To build insights into the vibrational behaviors of these materials, density functional theory (DFT) based Peierls-Boltzmann transport models have been developed and deployed to examine intrinsic and extrinsic phonon scatterings and resulting thermal conductivities (κ) as a function of alloy concentration (x) [13][14][15].…”

Manufacturing and performances of silicide-based thermoelectric modules

“…However, for medium temperature range applications, very few TE modules are available on the market today, while the need is real and the progress on the materials performance (expressed as the dimensionless TE figure of merit ZT: ZT S 2 T/ρκ, where T is the absolute temperature, S the Seebeck coefficient, ρ the electrical resistivity, and κ the thermal conductivity) is effective. Indeed, several new promising families of TE materials have been identified during these last two-three decades in this temperature range such as for instance skutterudites [14], Half-Heuslers [15], SnX (X Te, Se) [16,17] or silicide-based materials [18,19]. More details on the performances of all these materials, as well as others, can be found in recent general reviews [20,21].…”

“…More details on the performances of all these materials, as well as others, can be found in recent general reviews [20,21]. Among the silicides family, p-type Higher Manganese Silicide (HMS) and n-type Mg 2 (Si,Sn) solid solutions are particularly promising candidates as they are constituted of non-toxic, Earth-abundant, light, and low cost elements [22,23], while they exhibit high TE performance [18,19]. The objective of much of the recent investigations has clearly been to improve the figure of merit ZT by simultaneously decreasing the electrical resistivity and the thermal conductivity, which is a difficult task, by appropriate doping, band structure and/or microstructure engineering [24,25 and the references inside].…”

Bridgman Growth of Mg2Sn1–xBix Single Crystals and Anisotropic Thermoelectric Properties

“…Thermoelectric materials can achieve direct conversion between thermal energy and electrical energy. , Among these materials, nontoxic and nonpolluting candidates such as Mg-based alloys have aroused the intensive interest of researchers. − According to classical thermoelectric theory, the material factor β ∼ ( m */ m e ) 3/2 μκ L –1 can be used as the criterion for the selection of thermoelectric materials, where m * is the carrier effective mass, m e is the electron mass, μ is the mobility, and κ L is the lattice thermal conductivity. For Mg 2 X (X = Sn, Si, Ge), the β values are within a range between 3.7 and 14, which are much larger than those of SiGe alloys (β = 1.2 to 2.6) or β-FeSi 2 (β = 0.05 to 0.8). − Vining pointed out that zT max is proportional to β, whose value is defined as zT = S 2 σ T /κ. Thus, a material with a high zT value needs a high power factor (PF) S 2 σ as well as low thermal conductivity κ. ,, …”