Enhancing the Thermoelectric Performance of Self-Defect TiNiSn: A First-Principles Calculation

Rittiruam, Meena; Yangthaisong, A.; Seetawan, Tosawat

doi:10.1007/s11664-018-6686-7

Cited by 10 publications

(15 citation statements)

References 34 publications

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“…For instance, analyzing the Seebeck coefficient of TiNiSn using the Goldsmid-Sharp formula [62], Barczak et al [63] reported gradual reduction in the band gap with increasing amount of interstitial defect. In good agreement with this finding, ab initio studies showed that the structural interstitial defects reduce the band gap of TiNiSn [57,64,65]. These findings for TiNiSn indicate that intrinsic defects may, in general, play decisive role in determining the type of charge carriers and band gap of the above-mentioned half-Heusler alloys and help in solving the long-standing discrepancy between theoretical predictions and experimental observations for similar n-type half-Heusler alloys.…”

Section: Introductionsupporting

confidence: 67%

“…Unlike the usual tendency to predict underestimated band gap in solids [80][81][82][83][84], ab initio calculations yielded higher values of band gap in comparison to experimentally measured values for the above-mentioned half-Heusler alloys [48,[85][86][87]. It has been speculated that slight change in alloy composition in the experimental samples due to point defects may explain this deviation from the usual trend observed in semiconductors [57,64,65]. While external doping is the commonly employed point defect engineering strategy for tailoring carrier concentration and mobility [44][45][46][88][89][90][91][92][93][94], intrinsic point defects can also modify electronic structure, carrier concentration, and hence transport properties of half-Heusler alloys [95][96][97][98][99][100][101][102].…”

Section: B Electronic Band Structure and Density Of Statesmentioning

confidence: 56%

“…Figure 2 shows theoretically estimated point defect formation energies of the four half-Heusler alloys. Previous ab initio calculations for TiNiSn predicted Ni interstitial to be the most stable point defect in the alloy [57,64,65]. A comparison of the calculated and X-ray photoemission spectroscopy measured DOS further provided indirect evidence that excess Ni atoms occupy vacant 4d sites in the C1 b TiNiSn alloy [75].…”

Section: A Intrinsic Point Defectsmentioning

confidence: 81%

“…Next, we investigate the effect of interstitial defects on the electronic structure. Recent ab initio calculations focusing on the impact of interstitial Ni defects in TiNiSn revealed several noteworthy features in the electronic band structure and DOS [57,64,65]. The interstitial Ni leads to localized defect states close to the Fermi level within the band gap.…”

Section: B Electronic Band Structure and Density Of Statesmentioning

confidence: 99%

“…However, the half-Heusler alloys have been found to be prone to chemical off-stoichiometry [52,53]. The intrinsic point defects resulting in off-stoichiometric compositions have been previously reported for several half-Heusler alloys such as TiNiSn [54][55][56][57], HfNiSn [58,59], and ZrNiSn [33,60,61]. For instance, analyzing the Seebeck coefficient of TiNiSn using the Goldsmid-Sharp formula [62], Barczak et al [63] reported gradual reduction in the band gap with increasing amount of interstitial defect.…”

Section: Introductionmentioning

confidence: 99%

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Decisive role of interstitial defects in half-Heusler semiconductors: An ab initio study

Dey

Dutta

2021

Phys. Rev. Materials

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Half-Heusler semiconductors satisfying 18-electron rule typically display promising characteristics for thermoelectric applications. A persistent inconsistency between the type of charge carriers in some of these alloys as obtained from experiment and theory however casts serious doubt on the computational prediction of new and efficient half-Heusler alloys. To gain insights into the origin of this disparity, we have investigated the effect of intrinsic point defects on the electronic structure of four frequently studied half-Heusler alloys of the form XY Z with Y being Ni or Co. Using state-of-the-art ab initio calculations, our study reveals that interstitial Ni and Co are energetically most stable point defects in these alloys. Remarkably, interstitial defect modifies the location of the Fermi level inside the band gap as well as the value of the band gap, thereby bringing in close agreement with the corresponding experimental result. This work thus highlights the decisive role played by interstitial defects in thermoelectric half-Heusler alloys, which may open a new avenue for deliberately utilizing these defects as a strategy for tailoring electronic structure and hence the corresponding thermoelectric properties.

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Section: Introductionsupporting

confidence: 67%

Section: B Electronic Band Structure and Density Of Statesmentioning

confidence: 56%

Section: A Intrinsic Point Defectsmentioning

confidence: 81%

Section: B Electronic Band Structure and Density Of Statesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Decisive role of interstitial defects in half-Heusler semiconductors: An ab initio study

Dey

Dutta

2021

Phys. Rev. Materials

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First‐Principles Investigations on Effects of B‐Site Substitution (B═Mn, Fe, and Co) on La‐Based Perovskite Oxides As Bifunctional Electrocatalysts for Rechargeable Metal–Air Batteries

Somdee,

Rittiruam,

Saelee

et al. 2024

Advcd Theory and Sims

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The effects of B‐site substitution (B═Mn, Fe, and Co) in La‐based perovskite oxides (LPOs); LaMnO3, LaFeO3, LaCoO3, as bifunctional electrocatalysts during oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in metal–air batteries (MABs) under an alkaline electrolyte (pH = 13) are investigated using density functional theory (DFT). It is found that LaMnO3 exhibits higher ORR activity than others with ORR overpotential (ηORR) of 0.57 V, but its OER activity is poor with OER overpotential (ηOER) of 1.12 V. The ηORR (0.59 V) and ηOER (1.13 V) of LaMn0.75Fe0.25O3 closely resemble those of LaMnO3, suggesting that Fe substitution does not yield appreciable enhancements in activity. Fe substitution reduces the ORR and OER activity because the adsorption energies of intermediate species on Fe‐substituted LPOs surfaces are too strong to obtain a potential determining step for ORR and OER. According to Sabatier's principle, the LaMn0.25Co0.75O3 demonstrates superior OER activity compared to the other composition, while ORR activity approximates that of LaMnO3, evidenced by ηORR of 0.65 V and ηOER of 0.53 V. The Co‐terminated LaMn0.25Co0.75O3 shows bifunctional activity higher than Mn/Co termination, indicating that Co is an active site for OER and Mn is a promoter for improved ORR activity.

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The role of metal-doping on the enhanced electrocatalytic properties of α-MnO2 during oxygen reduction reaction

Rittiruam,

Aumnongpho,

Saelee

et al. 2024

Journal of Energy Storage

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Enhancing the Thermoelectric Performance of Self-Defect TiNiSn: A First-Principles Calculation

Cited by 10 publications

References 34 publications

Decisive role of interstitial defects in half-Heusler semiconductors: An ab initio study

Decisive role of interstitial defects in half-Heusler semiconductors: An ab initio study

First‐Principles Investigations on Effects of B‐Site Substitution (B═Mn, Fe, and Co) on La‐Based Perovskite Oxides As Bifunctional Electrocatalysts for Rechargeable Metal–Air Batteries

The role of metal-doping on the enhanced electrocatalytic properties of α-MnO2 during oxygen reduction reaction

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