Corrigendum to “On the relevance of point defects for the selection of contacting electrodes: Ag as an example for Mg2(Si,Sn)-based thermoelectric generators” [Mater. Today Phys. 16 (2021) 100309]

Achieving High Thermoelectric Performance in Severely Distorted YbCd2Sb2

“…[ 12,14,15,19,20 ] Traditionally, alloying has been applied as an effective method to introduce a large number of substitutional point defects and reduce lattice thermal conductivity. [ 21,22 ] The phonon scattering effect of these point defects is often considered as mass fluctuation and stress field fluctuation, and the expression of phonon relaxation time is [ 16,23 ] $$\[ \begin{array}{*{20}{c}}{\tau _{PD}^{ - 1} = \frac{{V{\omega ^4}}}{{4\pi {\nu ^3}}}({\Gamma _{\rm{M}}} + {\Gamma _{\rm{S}}})}\end{array} \]$$where V is the average atomic volume, v is the average sound speed. Γ M and Γ S are due to mass and strain field fluctuations and calculated by [ 23 ] $$\[ \begin{array}{*{20}{c}}{{\Gamma _{\rm{M}}} = \frac{{\mathop \sum \nolimits_{i = 1}^n {c_{\rm{i}}}{{\left( {\frac{{\overline {{M_{\rm{i}}}} }}{{\bar{M}}}} \right)}^2}}}{{\mathop \sum \nolimits_{i = 1}^n {c_{\rm{i}}}}}\mathop \sum \limits_k f_i^k{{\left( {1 - \frac{{M_{\rm{i}}^k}}{{\overline {{M_{\rm{i}}}} }}} \right)}^2}}\end{array} \]$$ …”

“…[12,14,15,19,20] Traditionally, alloying has been applied as an effective method to introduce a large number of substitutional point defects and reduce lattice thermal conductivity. [21,22] The phonon scattering effect of these point defects is often considered as mass fluctuation and stress field fluctuation, and the expression of phonon relaxation time is [16,23] 4 ( )…”

Optimization of the Thermoelectric Properties of p-Type Mg2–yLiyGe1–xSnx and Mg2–yLiyGe1–zSiz with x, z = 0.1 and 0.2

“…A possible explanation is that Li occupies both Mg and interstitial sites, thus serving simultaneously as a p-type and an n-type dopant. The previous report by Gao et al 18 suggested that Li can easily occupy both Mg (Li Mg ) substitutional and interstitial sites (Li int ) and it has also been noted by Kumari et al 42 and Ayachi et al, 43 in which the formation energy is lowest when Li occupies the Mg interstitial positions. These results from calculations are in contradiction to the experimental report by Nieroda et al, 44 which states that Li occupancy at the Mg site is more favorable.…”

High‐Performance Thermoelectric Devices Made Faster: Interface Design from First Principles Calculations

“…The nominal compositions were Mg 2.06 Si 0.3 Sn 0.665 Bi 0.035 and Mg 1.97 Li 0.03 Si 0.3 Sn 0.7 , and the samples were synthesized following a powder synthesis and sample compaction procedure reported in previous works, leading to state‐of‐the‐art TE properties. [ 6b,15a,c,23 ] The obtained pellets were contacted with Ti and Zn foils following the contacting procedure utilized in Ayachi et al. [ 6b ] Table 1 displays the different temperatures used for each electrode, whether tested in previous literature or presented as new data in this work.…”

“…Further research showed that this charge compensation mechanism is not strongly related to neither the newly grown reaction layer between the TE material and the electrodes nor the electrical sintering current that the samples are subjected to during the contacting procedure in the direct sinter press. [ 6b,c,10 ] Instead, it has been argued that the observed material degradation is majorly due to defect diffusion from the electrode to the TE material. Given the ubiquity of point defects and their crucial role in TE (and other) functional materials one might wonder why this problem has not appeared more prominently beforehand.…”