Grain refinement to improve thermoelectric and mechanical performance in n-type Bi2Te2.7Se0.3 alloys

Nagarjuna, Cheenepalli; Dharmaiah, Peyala; Kim, Ki Buem; Hong, Soon‐Jik

doi:10.1016/j.matchemphys.2020.123699

Cited by 20 publications

(12 citation statements)

References 40 publications

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“…The L can be determined from the experimental Seebeck coefficient using the following equation: L = 1.5 + exp[‐| S |/116]. [ 48 ] Then, the Lorenz‐corrected κ L + κ b (bipolar thermal conductivity) of all samples were calculated by κ L + κ b = κ – κ e and shown in (Figure 6c and Figure S9c, Supporting Information). The doping SbI 3 leads to an improvement of the phonon scattering and reduce the lattice thermal conductivity, also benefiting the improvement of TE performance.…”

Section: Resultsmentioning

confidence: 99%

Modulation of Vacancy Defects and Texture for High Performance n‐Type Bi₂Te₃ via High Energy Refinement

Zhou

Feng

et al. 2023

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The carrier concentration in n‐type layered Bi2Te3‐based thermoelectric (TE) material is significantly impacted by the donor‐like effect, which would be further intensified by the nonbasal slip during grain refinement of crushing, milling, and deformation, inducing a big challenge to improve its TE performance and mechanical property simultaneously. In this work, high‐energy refinement and hot‐pressing are used to stabilize the carrier concentration due to the facilitated recovery of cation and anion vacancies. Based on this, combined with SbI3 doping and hot deformation, the optimized carrier concentration and high texture degree are simultaneously realized. As a result, a peak figure of merit (zT) of 1.14 at 323 K for Bi2Te2.7Se0.3 + 0.05 wt.% SbI3 sample with the high bending strength of 100 Mpa is obtained. Furthermore, a 31‐couple thermoelectric cooling device consisted of n‐type Bi2Te2.7Se0.3 + 0.05 wt.% SbI3 and commercial p‐type Bi0.5Sb1.5Te3 legs is fabricated, which generates the large maximum temperature difference (ΔTmax) of 85 K at a hot‐side temperature of 343 K. Thus, the discovery of recovery effect in high energy refinement and hot‐pressing has significant implications for improving TE performance and mechanical strength of n‐type Bi2Te3, thereby promoting its applications in harsh conditions.

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Section: Resultsmentioning

confidence: 99%

Modulation of Vacancy Defects and Texture for High Performance n‐Type Bi₂Te₃ via High Energy Refinement

Zhou

Feng

et al. 2023

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“…As shown in Figure a, there is a slight increase in the total thermal conductivity when adding excess Te, due to the increase of electronic thermal conductivity (Figure b), which is calculated based on the Wiedemann–Franz law, k e = L σ T , where L is the Lorentz number, σ is the electrical conductivity, and T is the absolute temperature. L can be determined from the experimental Seebeck coefficient using the following equation: L = 1.5 + exp[−| S |/116] . As noted in the Debye model, the Umklapp scattering mechanism is dominant for phonon scattering above the Debye temperature and the relationship between k L and T is expressed as k L = aT –1 + b …”

Section: Results and Discussionmentioning

confidence: 99%

“…L can be determined from the experimental Seebeck coefficient using the following equation: L = 1.5 + exp[−|S|/116]. 40 As noted in the Debye model, the Umklapp scattering mechanism is dominant for phonon scattering above the Debye temperature and the relationship between k L and T is expressed as k L = aT −1 + b. 35 k L at the intrinsic excitation is first estimated by subtracting the k e from the k total within 300−350 K in this work and then extrapolating the lattice thermal conductivity at the subsequent temperature, which is presented in Figure 7c.…”

Section: Resultsmentioning

confidence: 99%

High Thermoelectric Performance of p-Type Bi_0.4Sb_1.6Te_3+x Synthesized by Plasma-Assisted Ball Milling

Liu

Zhu

Feng

et al. 2022

ACS Appl. Mater. Interfaces

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The exploration of new synthesis methods is important for the improvement of the thermoelectric property of a material for the different mechanisms of microstructure fabrication, surface activity modulation, and particle refinement. Herein, we prepared p-Bi2Te3 bulk materials by a simple synthesis method of the plasma-assisted ball milling, which yielded finer nanopowders, higher texture of in-plane direction, and higher efficiency compared to the traditional ball milling, favoring the simultaneous improvement of electrical and thermal properties. When combined with the Te liquid sintering, nano-/microscale hierarchical pores were fabricated and the carrier mobility was also increased, which together resulted in the low lattice thermal conductivity of 0.52 W·m–1·K–1 and the high power factor of 43.4 μW·cm–1·K–2 at 300 K, as well as the ranking ahead zT of 1.4@375 K. Thus, this work demonstrated the advantages of plasma-assisted ball milling in highly efficient synthesis of p-type Bi2Te3 with promising thermoelectric performance, which can also be utilized to prepare other thermoelectric materials.

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“…This increase in the relative intensity demonstrated that the grains are oriented along the c-axis. The broadening occurs, as seen in Figure 7 c, in between 40 and 50 of 2Ɵ indicates the grain refinement and high lattice strain [ 52 ]. The amorphization which can be observed from the decrease in the intensities of the peak has resulted from the graphite foil used during the sintering, where the increase in the intensity of the peak (1011) matched the highest peak intensity of the graphite.…”

Section: Resultsmentioning

confidence: 99%

Process Optimization of In Situ Magnetic-Anisotropy Spark Plasma Sintering of M-Type-Based Barium Hexaferrite BaFe12O19

et al. 2021

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This paper introduces a new spark plasma sintering technique that is able to order crystalline anisotropy by in-series/in situ DC electric coupled magnetic field. The process control parameters have been investigated on the production of anisotropic BaFe12O19 magnets based on resulted remanence (Mr). Sintering holding time (H.T.), cooling rate (C.R.), pressure (P), and sintering temperature (S.T.) are optimized by Taguchi with L9 orthogonal array (OA). The remanent magnetization of nanocrystalline BaFe12O19 in parallel (Mrǁ) and perpendicular (MrꞱ) to the applied magnetic field was regarded as a measure of performance. The Taguchi study calculated optimum process parameters, which significantly improved the sintering process based on the confirmation tests of BaFe12O19 anisotropy. The magnetic properties in terms of Mrǁ and MrꞱ were greatly affected by sintering temperature and pressure according to ANOVA results. In addition, regression models were developed for predicting the Mrǁ as well as MrꞱ respectively.

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Grain refinement to improve thermoelectric and mechanical performance in n-type Bi2Te2.7Se0.3 alloys

Cited by 20 publications

References 40 publications

Modulation of Vacancy Defects and Texture for High Performance n‐Type Bi₂Te₃ via High Energy Refinement

Modulation of Vacancy Defects and Texture for High Performance n‐Type Bi₂Te₃ via High Energy Refinement

High Thermoelectric Performance of p-Type Bi_0.4Sb_1.6Te_3+x Synthesized by Plasma-Assisted Ball Milling

Process Optimization of In Situ Magnetic-Anisotropy Spark Plasma Sintering of M-Type-Based Barium Hexaferrite BaFe12O19

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Grain refinement to improve thermoelectric and mechanical performance in n-type Bi2Te2.7Se0.3 alloys

Cited by 20 publications

References 40 publications

Modulation of Vacancy Defects and Texture for High Performance n‐Type Bi2Te3 via High Energy Refinement

Modulation of Vacancy Defects and Texture for High Performance n‐Type Bi2Te3 via High Energy Refinement

High Thermoelectric Performance of p-Type Bi0.4Sb1.6Te3+x Synthesized by Plasma-Assisted Ball Milling

Process Optimization of In Situ Magnetic-Anisotropy Spark Plasma Sintering of M-Type-Based Barium Hexaferrite BaFe12O19

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Product

Resources

About

Modulation of Vacancy Defects and Texture for High Performance n‐Type Bi₂Te₃ via High Energy Refinement

Modulation of Vacancy Defects and Texture for High Performance n‐Type Bi₂Te₃ via High Energy Refinement

High Thermoelectric Performance of p-Type Bi_0.4Sb_1.6Te_3+x Synthesized by Plasma-Assisted Ball Milling