Significantly enhanced thermoelectric figure of merit of p-type Mg<sub>3</sub>Sb<sub>2</sub>-based Zintl phase compounds via nanostructuring and employing high energy mechanical milling coupled with spark plasma sintering

Bhardwaj, A.; Chauhan, Nagendra S.; Misra, Debasmita

doi:10.1039/c5ta02155c

Cited by 87 publications

(52 citation statements)

References 62 publications

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“…[24] Since the beginning of this century, research attention has been paid to this compound but initial studies only focused on its p-type TE properties. [25][26][27] In 2016, Tamaki et al reported a prominent zT of 1.5 at 716 K in n-type Mg3.2Sb1.5Bi0.49Te0.01, and this result has soon been verified by independent groups. [20,21] Significant features contributing to the excellent TE performance have subsequently been identified.…”

Section: Introductionmentioning

confidence: 88%

Growth and transport properties of Mg3X2 (X = Sb, Bi) single crystals

Xin

Auffermann

et al. 2018

Materials Today Physics

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The discovery of high thermoelectric performance in n-type polycrystalline Mg3(Sb,Bi)2 based Zintl compounds has ignited intensive research interest. However, some fundamental questions concerning the anisotropic transport properties and the origin of intrinsically low thermal conductivity are still elusive, requiring the investigation of single crystals. In this work, high-quality p-type Mg3Sb2 and Mg3Bi2 single crystals have been grown by using a self-flux method. The electrical resistivity ρ of Mg3Bi2 single crystal displays an anisotropy with ρ in-plane twice larger than out-of-plane. The low-temperature heat capacity and lattice thermal conductivity of Mg3Sb2 and Mg3Bi2 single crystals have been investigated by using the Debye-Callaway model, from which the existence of low-lying vibration mode could be concluded. Large Grüneisen parameters and strong anharmonicity are found responsible for the intrinsically low thermal conductivity. Moreover, grain boundary scattering does not contribute significantly to suppress the lattice thermal conductivity of polycrystalline Mg3Sb2. Our results provide insights into the intrinsic transport 2 properties of Mg3X2 and could pave a way to realize enhanced thermoelectric performance in single-crystalline Mg3X2-based Zintl compounds.

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Section: Introductionmentioning

confidence: 88%

Growth and transport properties of Mg3X2 (X = Sb, Bi) single crystals

Xin

Auffermann

et al. 2018

Materials Today Physics

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“…Pure Mg 3 Sb 2 is intrinsically p-type, and many attempts at doping or substituting with a series of elements result in p-type behaviors as well. [38][39][40][41][42][43][44][45][46][47][48][49][50]52,102,[126][127][128][129][130] This is because of the low formation energies of the negatively charged Mg vacancies (V 2À Mg1 and V 2À Mg2 ) (Fig. 8), which prevent the chemical potential from moving close to the conduction bands for the Sbrich condition.…”

Section: Multi-valley Conduction Bands Complex Fermi Surface and Exmentioning

confidence: 99%

Insights into the design of thermoelectric Mg3Sb2 and its analogs by combining theory and experiment

2019

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Over the past two decades, we have witnessed a strong interest in developing Mg 3 Sb 2 and related CaAl 2 Si 2 -type materials for lowand intermediate-temperature thermoelectric applications. In this review, we discuss how computations coupled with experiments provide insights for understanding chemical bonding, electronic transport, point defects, thermal transport, and transport anisotropy in these materials. Based on the underlying insights, we examine design strategies to guide the further optimization and development of thermoelectric Mg 3 Sb 2 -based materials and their analogs. We begin with a general introduction of the Zintl concept for understanding bonding and properties and then reveal the breakdown of this concept in AMg 2 X 2 with a nearly isotropic three-dimensional chemical bonding network. For electronic transport, we start from a simple yet powerful atomic orbital scheme of tuning orbital degeneracy for optimizing p-type electrical properties, then discuss the complex Fermi surface aided by high valley degeneracy, carrier pocket anisotropy, and light conductivity effective mass responsible for the exceptional n-type transport properties, and finally address the defect-controlled carrier density in relation to the electronegativity and bonding character. Regarding thermal transport, we discuss the insight into the origin of the intrinsically low lattice thermal conductivity in Mg 3 Sb 2 . Furthermore, the anisotropies in electronic and thermal transport properties are discussed in relation to crystal orbitals and chemical bonding. Finally, some specific challenges and perspectives on how to make further developments are presented.npj Computational Materials (2019) 5:76 ; https://doi.

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“…Now we consider that the average value of κ in polycrystalline samples will be determined by the grain size distribution and shape. We thus investigate the size dependence of κ , and set up a simple estimate based on actual grain distributions [6]. Figure 2 reports the sizedependent κ (L) (the usual inverse average of the components) at 300 K, along with the normalized grain-size distribution n L , imported from Figure 3a Evidently, the grain distribution is quite localized over small values (about 20 nm on average) and becomes negligible at larger values.…”

mentioning

confidence: 99%

Ab initiothermal conductivity of thermoelectricMg3Sb2: Evidence for dominant extrinsic effects

2018

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Significantly enhanced thermoelectric figure of merit of p-type Mg₃Sb₂-based Zintl phase compounds via nanostructuring and employing high energy mechanical milling coupled with spark plasma sintering

Abstract: Several nanostructuring methods have been demonstrated to produce a variety of nanostructured materials, and these methods are well recognized as effective paradigms for improving the performance of thermoelectric materials.

Cited by 87 publications

References 62 publications

Growth and transport properties of Mg3X2 (X = Sb, Bi) single crystals

Growth and transport properties of Mg3X2 (X = Sb, Bi) single crystals

Insights into the design of thermoelectric Mg3Sb2 and its analogs by combining theory and experiment

Ab initiothermal conductivity of thermoelectricMg3Sb2: Evidence for dominant extrinsic effects

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Significantly enhanced thermoelectric figure of merit of p-type Mg3Sb2-based Zintl phase compounds via nanostructuring and employing high energy mechanical milling coupled with spark plasma sintering

Abstract: Several nanostructuring methods have been demonstrated to produce a variety of nanostructured materials, and these methods are well recognized as effective paradigms for improving the performance of thermoelectric materials.

Cited by 87 publications

References 62 publications

Growth and transport properties of Mg3X2 (X = Sb, Bi) single crystals

Growth and transport properties of Mg3X2 (X = Sb, Bi) single crystals

Insights into the design of thermoelectric Mg3Sb2 and its analogs by combining theory and experiment

Ab initiothermal conductivity of thermoelectricMg3Sb2: Evidence for dominant extrinsic effects

Contact Info

Product

Resources

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Significantly enhanced thermoelectric figure of merit of p-type Mg₃Sb₂-based Zintl phase compounds via nanostructuring and employing high energy mechanical milling coupled with spark plasma sintering