Thermoelectric properties and stability of nanostructured chromium disilicide CrSi2

Khalil, Mahmoud; Moll, Adrien; Godfroy, Maxime; Letrouit-Lebranchu, Angélique; Villeroy, Benjamin; Alleno, É.; Viennois, R.; Beaudhuin, M.

doi:10.1063/1.5117152

Cited by 17 publications

(21 citation statements)

References 21 publications

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Section: Thermoelectric Propertiesmentioning

confidence: 96%

“…An even larger effect was demonstrated in the case of n-doped silicon in which the thermal conductivity was divided by 15 and the ZT increased from 0.2 to 0.7 at 1273 K [19]. We also demonstrated a significant reduction of the thermal conductivity in several transition metal silicides through nanostructuration [20][21][22]. In this study, we investigated the effect of the nanostructuration on thermoelectric properties by combining a top-down approach coupled with Spark Plasma Sintering (SPS) on β-FeSi 2 and one of the best Co-alloys β-Fe 0.95 Co 0.05 Si 2 .…”

Section: Introductionmentioning

confidence: 91%

“…Figure 6a presents the decrease in the electrical resistivity of the annealed and nanostructured samples with temperature dependence which is typical of a semi-conductor. The electrical resistivity of the nanostructured sample is higher than the annealed sample due to an increase in electron scattering at the interfaces and by an increase in point defects due to mechanical milling [22]. The Seebeck's coefficient is quite similar between both samples with a maximum of the thermopower that can be explained either by the change from low temperature extrinsic to high-temperature intrinsic conduction, which is characteristic of a change from heavily doped to lightly doped semiconductor [30] or by bipolar conduction effect as, e.g., in Bi 2 Te 3 based alloys [31,32].…”

Section: Thermoelectric Propertiesmentioning

confidence: 99%

“…It is slightly lower for the S4 sample and can be explained by the grain coarsening and the decrease in point defects in S4 ann. samples which lead to an increase in the phonon relaxation rate [22].…”

Section: Thermoelectric Propertiesmentioning

confidence: 99%

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Effect of Nanostructuring on the Thermoelectric Properties of β-FeSi2

et al. 2021

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Nanostructured β-FeSi2 and β-Fe0.95Co0.05Si2 specimens with a relative density of up to 95% were synthesized by combining a top-down approach and spark plasma sintering. The thermoelectric properties of a 50 nm crystallite size β-FeSi2 sample were compared to those of an annealed one, and for the former a strong decrease in lattice thermal conductivity and an upshift of the maximum Seebeck’s coefficient were shown, resulting in an improvement of the figure of merit by a factor of 1.7 at 670 K. For β-Fe0.95Co0.05Si2, one observes that the figure of merit is increased by a factor of 1.2 at 723 K between long time annealed and nanostructured samples mainly due to an increase in the phonon scattering and an increase in the point defects. This results in both a decrease in the thermal conductivity to 3.95 W/mK at 330 K and an increase in the power factor to 0.63 mW/mK2 at 723 K.

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Section: Thermoelectric Propertiesmentioning

confidence: 96%

Section: Introductionmentioning

confidence: 91%

Section: Thermoelectric Propertiesmentioning

confidence: 99%

Section: Thermoelectric Propertiesmentioning

confidence: 99%

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Effect of Nanostructuring on the Thermoelectric Properties of β-FeSi2

et al. 2021

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“…Metal silicides have been used in high-temperature structural applications because of their advantages such as high-temperature strength and oxidation resistance, among others. Additionally, metal silicides can be used as protective coatings on engineering materials to protect them from corrosion in harsh environments [2][3][4].…”

Section: Introductionmentioning

confidence: 99%

Effect of the Deposition Time and Heating Temperature on the Structure of Chromium Silicides Synthesized by Pack Cementation Process

Tarani

Stathokostopoulos

Tsipas

et al. 2021

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Transition metal silicides have attracted great interest for their potential use in optoelectronic devices, photovoltaic cells, and thermoelectric conversion elements because of their high melting point, high oxidation resistance, and satisfactory thermoelectric properties. This study focuses on the effect of the deposition time and the heating temperature on the morphology and structure of the chromium silicides synthesized by the pack cementation method. A series of experiments were carried out at various temperatures (1000–1150 °C) with different deposition times (15–120 min). The morphology and the chemical composition of the samples were determined using SEM with an EDS analyzer. The structure determination and phase identification were performed by XRD analysis. The examination of the as-formed materials was completed by performing thermal stability tests. The most suitable conditions for producing CrSi2 sample with satisfactory properties and simultaneously minimizing the cost and production time are listed. It was found that the sample synthesized at 1000 °C for 15 min during the chromizing step, in combination with the siliconizing step at 1000 °C for 60 min, presents the best thermal stability and these selected temperatures offer appropriate, economical, and repeatable results.

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