Crystallographic design for half-Heuslers with low lattice thermal conductivity

Ren, Wuyang; Shi, Xin; Wang, Zhiming; Ren, Zhifeng

doi:10.1016/j.mtphys.2022.100704

Cited by 22 publications

(21 citation statements)

References 119 publications

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“…Meanwhile, the major drawback of thermoelectric HHs-their intrinsically high lattice thermal conductivity (κ lat )-has been addressed to some extent (Fig. 1) 18,22,23 . For instance, the room-temperature κ lat of defective Nb 0.8 CoSb is ~ 4.2 W m − 1 K − 1 , while that of NbCoSn is ~ 7.7 W m − 1 K − 1 .…”

Section: Introductionmentioning

confidence: 99%

Vacancy-mediated anomalous phononic and electronic transport in defective half-Heusler ZrNiBi

Ren

Xue

Guo

et al. 2023

Preprint

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Studies of vacancy-mediated anomalous transport properties have flourished in diverse fields since they endow solid materials with fascinating photoelectric, ferroelectric, and spin-electric behaviors. Although phononic and electronic transport underpin the physical origin of thermoelectrics, vacancy has only played a stereotyped role as a scattering center. Here we reveal the multifunctionality of vacancy in tailoring the transport properties of an emerging thermoelectric material, defective n-type ZrNiBi. The phonon kinetic process is mediated in both propagating velocity and relaxation time: vacancy-induced local soft bonds lower the phonon velocity while acoustic-optical phonon coupling, anisotropic vibrations, and point-defect scattering induced by vacancy shorten the relaxation time. Consequently, defective ZrNiBi exhibits the lowest lattice thermal conductivity among the half-Heusler family. In addition, a vacancy-induced flat band features prominently in its electronic band structure, which is not only desirable for electron-sufficient thermoelectric materials but also interesting to drive other novel physical phenomena. Finally, better thermoelectric performance is established in a ZrNiBi-based compound. Our findings not only demonstrate a promising thermoelectric material but also promote the fascinating vacancy-mediated anomalous transport properties for multidisciplinary explorations.

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Section: Introductionmentioning

confidence: 99%

Vacancy-mediated anomalous phononic and electronic transport in defective half-Heusler ZrNiBi

Ren

Xue

Guo

et al. 2023

Preprint

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“…The lower lattice thermal conductivity (κ l ) due to lattice distortion and an improvement of the power factor due to high crystal symmetry make high-entropy alloys (HEAs) prospective TE materials . Similarly, Ren et al showed that aliovalent substitution could form double, triple, or quadruple HH, where the combination of the increasing complexity of the crystal structure by virtue of an increase in effective N (number of atoms in the unit cell) and an order–disorder transition at elevated temperatures lowers the value of κ l . For instance, substituting Ni and Fe instead of Co in TiCoSb to form TiFe 0.5 Ni 0.5 Sb double half-Heusler exhibited roughly 35% lower thermal conductivity .…”

Section: Introductionmentioning

confidence: 99%

Low-Lattice Thermal Conductivity in Zr-Doped Ti₂NiCoSnSb Thermoelectric Double Half-Heusler Alloys

Mishra

Tan

Trivedi

et al. 2023

ACS Appl. Energy Mater.

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The effect of doping on the thermoelectric properties of Half-Heusler (HH) high-entropy alloy (HEA) Ti2NiCoSnSb was studied. Lower thermal conductivity was observed with increased Sb doping. Mass scattering by heavy (Ta, Zr) and light (Al) dopants was studied to further lower the thermal conductivity. Dopants at the level of up to 50% at the Ti site were studied. A high HH phase content was obtained in the Zr-doped samples, and a low-lattice thermal conductivity of 1.9 W/(m·K) was observed. This value is one of the lowest reported lattice thermal conductivities in HH alloys. The poor solubility of Ta led to undissolved Ta in the samples, which enhanced the electrical properties. In the case of Al doping, the NiAl phase raised the power factor value of Ti1.8Al0.2NiCoSn0.5Sb1.5 to 2.2 × 10–3 W/(m·K2), which is almost twice the corresponding value reported for Ti2NiCoSnSb. Interestingly, a maximum ZT of 0.29 was found in all of the doped systems, although the transport mechanism and microstructure varied widely with the type of dopant. An optimum dopant level of 25% of Zr, 7.5% of Ta, and 10% of Al is necessary to obtain the maximum ZT in these alloys. Compared to HH systems, the HH high-entropy alloy (HEA) systems provide a larger composition field for tuning the transport properties by simultaneous doping of multiple elements to lower the thermal conductivity.

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“…On one hand, from the perspective of materials exploitation to practically apply thermoelectric power generation, actively searching for materials with intrinsically good thermoelectric performance is an essential route, and there have been several series of materials, such as Bi 2 Te 3 , [1][2][3] Zintls, [4][5][6][7][8] Group IVÀ VI semiconductors, [9][10][11][12][13][14][15][16] half-Heuslers, [17][18][19] SiGe, [20][21][22] etc., that have shown great potential. On the other hand, it is also pivotal to improve the thermoelectric performance of existing materials through exotic structure modifications, both crystallographic and electronic, so that these structures may enable more beneficial advantages like a reduced sound velocity, [23] an optimized bandwidth, [24] converged valence/conduction bands, [25,26] and others.…”

Section: Introductionmentioning

confidence: 99%

When IV−VI Meets I−V−VI₂: A Reinvigorating Thermoelectric Strategy for Tin Monochalcogenides

Shi

Ren

2022

ChemNanoMat

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Resembling the widely studied PbTeÀ AgSbTe 2 (LAST) and GeTeÀ AgSbTe 2 (TAGS) thermoelectric materials, alloying group IÀ VÀ VI 2 compounds to tin monochalcogenides (SnTe, SnSe, and SnS) was also initially studied in the 1960s. Nevertheless, this thermoelectric strategy has regained popularity only in recent years, and boosted performance is now generally expected in these alloys. Given its encouraging revival and the absence of a corresponding research summary, here we carefully review current advances in this system, which is categorized into three major subgroups, that is, IÀ SbÀ VI 2 -alloyed SnTe, IÀ BiÀ VI 2 -alloyed SnTe, and IÀ SbÀ VI 2alloyed SnSe. Emphasis is placed on exploring the underlying mechanisms of this system in addition to its thermoelectric properties. Some future directions of this reinvigorating strategy are also proposed in the hope that they can serve as a guide for its further exploration.

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Crystallographic design for half-Heuslers with low lattice thermal conductivity

Cited by 22 publications

References 119 publications

Vacancy-mediated anomalous phononic and electronic transport in defective half-Heusler ZrNiBi

Vacancy-mediated anomalous phononic and electronic transport in defective half-Heusler ZrNiBi

Low-Lattice Thermal Conductivity in Zr-Doped Ti₂NiCoSnSb Thermoelectric Double Half-Heusler Alloys

When IV−VI Meets I−V−VI₂: A Reinvigorating Thermoelectric Strategy for Tin Monochalcogenides

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Crystallographic design for half-Heuslers with low lattice thermal conductivity

Cited by 22 publications

References 119 publications

Vacancy-mediated anomalous phononic and electronic transport in defective half-Heusler ZrNiBi

Vacancy-mediated anomalous phononic and electronic transport in defective half-Heusler ZrNiBi

Low-Lattice Thermal Conductivity in Zr-Doped Ti2NiCoSnSb Thermoelectric Double Half-Heusler Alloys

When IV−VI Meets I−V−VI2: A Reinvigorating Thermoelectric Strategy for Tin Monochalcogenides

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Product

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Low-Lattice Thermal Conductivity in Zr-Doped Ti₂NiCoSnSb Thermoelectric Double Half-Heusler Alloys

When IV−VI Meets I−V−VI₂: A Reinvigorating Thermoelectric Strategy for Tin Monochalcogenides