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Enhanced thermoelectric properties of Zintl phase YbMg_(2)Bi1.98 through Bi site substitution with Sb

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Journal of Materials Science & Technology 2020年第24期59卷 189-194页

作者： Jing Wang Muchun Guo Jianbo Zhu Dandan Qin Fengkai Guo Qian Zhang Wei Cai jiehe sui National Key Laboratory for Precision Hot Processing of Metals Harbin Institute of TechnologyHarbin150001China Department of Materials Science and Engineering Harbin Institute of TechnologyShenzhenShenzhen518055China

Benefiting from the unique"Phonon-Glass,Electron-Crystal"(PGEC)characteristic,Zintl phases have been considered as a kind of promising thermoelectric *** the typical AM2X2 compounds with the CaAl2Si2-type structure,YbMg_(2)Bi2 has shown competitive thermoelectric performance ***,the optimization of YbMg_(2)Bi2 compounds is primarily focused on the substitution on Yb or Mg ***,the Bi site is substituted by isoelectric Sb and the effect on the thermoelectric transport behavior is *** partial substitution reduces the carrier concentration and induces the lattice deformation caused by the different atomic radius and mass between Bi and Sb,further leading to the decreased power factor and thermal ***,the reduction extent of the thermal conductivity outperforms that of power ***,the Sb substitution successfully results in a better thermoelectric performance compared with that of the pristine YbMg_(2)***,the calculated energy conversion efficiency(a)of YbMg_(2)Bi1.88Sb0.1 which also possesses a relatively high output power density reaches the maximum value of 9.8% when Th=873 K,and Tc=300 K,*** work demonstrates that the idea of substitution on anionic site should be a new strategy to achieve better ZT values for AM2X2 compounds.

关键词： Zintl phase YbMg_(2)Bi2 Anionic substitution Thermoelectric properties

Achieving High Thermoelectric Performance in Rare-Earth Element-Free CaMg_(2)Bi_(2) with High Carrier Mobility and Ultralow Lattice Thermal Conductivity

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Research 2020年第1期2020卷 824-833页

作者： Muchun Guo Fengkai Guo Jianbo Zhu Li Yin Qian Zhang Wei Cai jiehe sui National Key Laboratory for Precision Hot Processing of Metals Harbin Institute of TechnologyHarbin 150001China Department of Materials Science and Engineering Harbin Institute of TechnologyShenzhenGuangdong 518055China

CaMg_(2)Bi_(2)-based compounds,a kind of the representative compounds of Zintl phases,have uniquely inherent layered structure and hence are considered to be potential thermoelectric ***,alloying is a traditional and effective way to reduce the lattice thermal conductivity through the mass and strain field fluctuation between host and guest *** cation sites have very few contributions to the band structure around the fermi level;thus,cation substitution may have negligible influence on the electric transport *** is more,widespread application of thermoelectric materials not only desires high ZT value but also calls for low-cost and environmentally benign constituent ***,Ba substitution on cation site achieves a sharp reduction in lattice thermal conductivity through enhanced point defects scattering without the obvious sacrifice of high carrier mobility,and thus improves thermoelectric ***,by combining further enhanced phonon scattering caused by isoelectronic substitution of Zn on the Mg site,an extraordinarily low lattice thermal conductivity of 0.51Wm^(-1) K^(-1) at 873 K is achieved in(Ca_(0.75)Ba_(0.25))_(0.995)Na_(0.005)Mg_(1.95)Zn_(0.05)Bi_(1.98) alloy,approaching the amorphous *** maintenance of high mobility and realization of ultralow lattice thermal conductivity synergistically result in broadly improvement of the quality factorβ.Finally,a maximum ZT of 1.25 at 873K and the corresponding ZTave up to 0.85 from 300 K to 873K have been obtained for the same composition,meanwhile possessing temperature independent compatibility *** our knowledge,the current ZTave exceeds all the reported values in AMg_(2)Bi_(2)-based compounds so ***,the low-cost and environmentfriendly characteristic plus excellent thermoelectric performance also make the present Zintl phase CaMg_(2)Bi_(2) more competitive in practical application.

关键词： alloying substitution Rare

Electronic Orbital Alignment and Hierarchical Phonon Scattering Enabling High Thermoelectric Performance p-Type Mg_(3)Sb_(2) Zintl Compounds

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Research 2022年第4期2022卷 107-118页

作者： Jinsuo Hu Jianbo Zhu Fengkai Guo Haixu Qin Yijie Liu Qian Zhang Zihang Liu Wei Cai jiehe sui State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China Department of Materials Science and Engineering Harbin Institute of TechnologyShenzhen 518055China

Environmentally friendly Mg_(3)Sb_(2)-based materials have drawn intensive attention owing to their promising thermoelectric *** this work,the electrical properties of p-type Mg_(3)Sb_(2) are dramatically optimized by the regulation of Mg ***,we,for the first time,found that Zn substitution at the Mg2 site leads to the alignment of px,y and pz orbital,resulting in a high band degeneracy and the dramatically enhanced Seebeck coefficient,demonstrated by the DFT calculations and electronic properties ***,Zn alloying decreases Mg1(Zn)vacancies formation energy and in turn increases Mg(Zn)vacancies and optimizes the carrier ***,the Mg/Zn substitutions,Mg vacancies,and porosity structure suppress the phonon transport in a broader frequency range,leading to a low lattice thermal conductivity of~0.47 W m^(-1) K^(-1) at 773 ***,a high ZT of~0.87 at 773 K was obtained for Mg_(1.95)Na_(0.01)Zn_(1)Sb_(2),exceeding most of the previously reported p-type Mg_(3)Sb_(2) *** results further demonstrate the promising prospects of p-type Mg_(3)Sb_(2)-based material in the field of mid-temperature heat recovery.

关键词： alloying Orbital exceeding

Restructured single parabolic band model for quick analysis in thermoelectricity

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npj Computational Materials 2021年第1期7卷 1053-1060页

作者： Jianbo Zhu Xuemei Zhang Muchun Guo Jingyu Li Jinsuo Hu Songting Cai Wei Cai Yongsheng Zhang jiehe sui National Key Laboratory for Precision Hot Processing of Metals Harbin Institute of TechnologyHarbinChina Key Laboratory of Materials Physics Institute of Solid State PhysicsChinese Academy of SciencesHefeiChina Science Island Branch of Graduate School University of Science and Technology of ChinaHefeiChina Department of Materials Science and Engineering Northwestern UniversityEvanstonILUSA

The single parabolic band(SPB)model has been widely used to preliminarily elucidate inherent transport behaviors of thermoelectric(TE)materials,such as their band structure and electronic thermal conductivity,***,in the SPB calculation,it is necessary to determine some intermediate variables,such as Fermi level or the complex Fermi-Dirac *** this work,we establish a direct carrier-concentration-dependent restructured SPB model,which eliminates Fermi-Dirac integrals and Fermi level calculation and emerges stronger visibility and usability in *** have verified the reliability of such restructured model with 490 groups of experimental data from state-of-the-art TE materials and the relative error is less than 2%.Moreover,carrier effective mass,intrinsic carrier mobility and optimal carrier concentration of these materials are systematically *** believe that our work can provide more convenience and accuracy for thermoelectric data analysis as well as instructive understanding on future optimization design.

关键词： parabolic Fermi instru

Graphene-enhanced thermoelectric properties of p-type skutterudites

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Chinese Physics B 2018年第4期27卷 123-126页

作者： Dandan Qin Yuan Liu Xianfu Meng Bo Cui Yaya Qi Wei Cai jiehe sui State Key Laboratory of Advanced Welding and Joining Harbin Institute of Technology Harbin 150001 China Department of Physics and TcSUH University of Houston Houston Texas 77204 USA Fresenius Kabi USA LLC Melrose Park IL 60160 USA

Nanocomposite is proved to be an effective method to improve thermoelectric *** the present study,graphene is introduced into p-type skutterudite La0.8Ti0.1Ga0.1Fe3CoSb12 by plasma-enhanced chemical vapor deposition（PECVD）method to form skutterudite/graphene *** is demonstrated that the graphene has no obvious effect on the electrical conductivity of La0.8Ti0.1Ga0.1Fe3CoSb12,but the Seebeck coefficient is slightly improved at high temperature,thereby leading to high power ***,due to the enhancement of phonon scattering by the graphene,the lattice thermal conductivity is reduced ***,the maximum z T value of La0.8Ti0.1Ga0.1Fe3CoSb12/graphene is higher than that of graphene-free alloy and reaches to 1.0 at 723 *** an approach raised by us enriches prospects for future practical application.

关键词： skutterudites graphene nanocomposites thermoelectric properties

Promoted application potential of p-type Mg_(3)Sb_(1.5)Bi_(0.5)for thematched thermal expansion with its n-type counterpart

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Journal of Materiomics 2020年第4期6卷 729-735页

作者： Jinsuo Hu Fengkai Guo Muchun Guo Jianbo Zhu Chen Chen Qian Zhang Wei Cai jiehe sui National Key Laboratory for Precision Hot Processing of Metals Harbin Institute of TechnologyHarbin150001China Department of Materials Science and Engineering Harbin Institute of TechnologyShenzhenGuangdong518055China

Recently,n-type Mg3Sb1.5Bi0.5-based thermoelectric materials have attracted considerable attention for their extraordinary thermoelectric ***,thermoelectric generators should be made of the same material system to avoid thermal mismatch in the practical *** this work,p-type Mg3Sb1.5Bi0.5 which has almost the same composition as the state-of-the-art n-type Mg3.2Sb1.5Bi0.49-Te0.01Mn0.01 was synthesized by ball milling and spark plasma sintering,and then Na was chosen as an acceptor dopant to optimize the carrier concentration and further improve the thermoelectric ***0.0075Mg2.9925Sb1.5Bi0.5 sample gets the highest ZT of~0.5 at 773 *** Na0.005Mg2.995Sb1.5Bi0.5 sample shows the highest average ZT of~0.29 in the temperature range of 300 e773 K and matched thermal expansion behavior with the state-of-the-art n-type Mg3.2Sb1.5Bi0.49-Te0.01Mn0.01,which is of great significance for practical *** the Joule and Thompson heat into account,a high theoretical conversion efficiency(η)of~9.5%was calculated for the thermoelectric module consists of the present p-type Na0.005Mg2.995Sb1.5Bi0.5 and the state-of-the-art n-type Mg3.2Sb1.5Bi0.49Te0.01Mn0.01 with the leg length of 2 mm,and cold and hot side temperature of 300 K and 773 K,respectively,which shows a good potential for the use of this class of materials in the midtemperature power generation applications.

关键词： Thermoelectric Zintl phase p-type Mg_(3)Sb_(1.5)Bi_(0.5) Thermal expansion behavior Theoretical conversion efficiency

Preparation of multi-walled carbon nanotube-reinforced TiNi matrix composites from elemental powders by spark plasma sintering

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Rare Metals 2012年第1期31卷 48-50页

作者： CAI Wei,FENG Xue,and sui jiehe National Key Laboratory Precision Hot Processing of Metals,School of Materials Science and Engineering,Harbin Institute of Technology,Harbin 150001,China National Key Laboratory Precision Hot Processing of Metals School of Materials Science and Engineering Harbin Institute of Technology Harbin China

Carbon nanotube (CNT)-reinforced TiNi matrix composites were synthesized by spark plasma sintering (SPS) employing elemental *** phase structure,morphology and transformation behaviors were *** was found that thermoelastic martensitic transformation be-haviors could be observed from the samples sintered above 800 ℃ even with a short sintering time (5min),and the transformation tempera-tures gradually increased with increasing sintering temperature because of more Ti-rich TiNi phase *** decreasing the sin-tering temperature and time to 700 ℃ and 5min could not protect defective MWCNTs from reacting with Ti,still-perfect MWCNTs re-mained in the specimens sintered at 900 ℃.This method is expected to supply a basis for preparing CNT-reinforced TiNi composites.

关键词： metallic composites shape memory materials carbon nanotubes spark plasma sintering

Enhanced thermoelectric performance in Ti(Fe, Co, Ni)Sb pseudoternary Half-Heusler alloys

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Journal of Materiomics 2021年第4期7卷 756-765页

作者： Qingmei Wang Xiaodong Xie Shan Li Zongwei Zhang Xiaofang Li Honghao Yao Chen Chen Feng Cao jiehe sui Xingjun Liu Qian Zhang School of Materials Science and Engineering Institute of Materials Genome&Big DataHarbin Institute of TechnologyShenzhen518055China School of Science Harbin Institute of TechnologyShenzhen518055China State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin150001China

TiFe0.5Ni0.5Sb-based half-Heusler compounds have the intrinsic low lattice thermal conductivity and the adjustable band *** by the previously reports to achieve both p-and n-type components by tuning the ratio of Fe and Ni based on the same parent TiFe0.5Ni0.5Sb,we selected Co as the amphoteric dopants to prepare both n-type and p-type pseudo-ternary Ti(Fe,Co,Ni)Sb-based halfHeusler *** carrier concentration,as well as the density of states effective mass was significantly increased by Co doping,contributing to the enhanced power factor of 1.80 mW m^(-1) K^(-2) for n-type TiFe0.3Co_(0.2)Ni_(0.5)Sb and 2.21 mW m^(-1) K^(-2) for p-type TiFe_(0.5)Co_(0.15)Ni_(0.35)Sb at 973 *** with the further decreased lattice thermal conductivity due to the strain field and mass fluctuation scattering induced by alloying Hf on the Ti site,peak ZTs of 0.65 in n-type Ti0.8Hf_(0.2)Fe_(0.3)Co_(0.2)Ni_(0.5)Sb and 0.85 in ptype Ti0.8Hf_(0.2)Fe_(0.5)Co_(0.15)Ni_(0.35)Sb were achieved at 973 K,which is of great significance for the thermoelectric power generation applications.

关键词： Thermoelectric Half-Heusler TiFe0.5Ni0.5Sb Carrier concentration Lattice thermal conductivity

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半导体ZnO亚微米钉的合成与表征

稀有金属材料与工程 2008年第3期37卷 547-550页

作者：武祥隋解和蔡伟哈尔滨工业大学黑龙江哈尔滨150001

使用热蒸发法合成了一种亚微米级的钉状结构ZnO。扫描电镜和X射线衍射分析表明:使用这种方法合成的钉状ZnO具有六方纤锌矿结构;ZnO亚微米钉结构的杆部直径范围在200～400nm之间,底座部分的直径一般大于400nm,有些甚至大到微米级;由于没... 详细信息

使用热蒸发法合成了一种亚微米级的钉状结构ZnO。扫描电镜和X射线衍射分析表明:使用这种方法合成的钉状ZnO具有六方纤锌矿结构;ZnO亚微米钉结构的杆部直径范围在200～400nm之间,底座部分的直径一般大于400nm,有些甚至大到微米级;由于没有使用催化剂,因此推测这种ZnO亚微米钉的生长过程很可能遵循气-固生长机制。此外,还研究了这种ZnO亚微米钉结构的发光特性。

关键词：半导体 ZnO 亚微米钉合成