Using the 18-Electron Rule To Understand the Nominal 19-Electron Half-Heusler NbCoSb with Nb Vacancies
Abstract
The 18-electron rule is a widely used criterion in the search for new half-Heusler thermoelectric materials. However, several 19-electron compounds such as NbCoSb have been found to be stable and exhibit thermoelectric properties rivaling state-of-the art materials. Using synchrotron X-ray diffraction and density functional theory calculations, we show that samples with nominal (19-electron) composition NbCoSb actually contain a half-Heusler phase with composition Nb0.84CoSb. The large amount of stable Nb vacancies reduces the overall electron count, which brings the stoichiometry of the compound close to an 18-electron count, and stabilizes the material. Excess electrons beyond 18 electrons provide heavy doping needed to make these good thermoelectric materials. This work demonstrates that considering possible defect chemistry and allowing small variation of electron counting leads to extra degrees of freedom for tailoring thermoelectric properties and exploring new compounds. Here we discuss the 18-electron rule as a guide to find defect-free half-Heusler semiconductors. As a result, other electron counts such as 19-electron NbCoSb can also be expected to be stable as n-type metals, perhaps with cation vacancy defects to reduce the electron count.
- Authors:
-
- Justus-Liebig-Univ. Giessen, Giessen (Germany)
- Northwestern Univ., Evanston, IL (United States)
- Xihua Univ., Sichuan (China)
- Univ. of Houston, Houston, TX (United States)
- Publication Date:
- Research Org.:
- Energy Frontier Research Centers (EFRC) (United States). Solid-State Solar-Thermal Energy Conversion Center (S3TEC)
- Sponsoring Org.:
- USDOE Office of Science (SC), Basic Energy Sciences (BES)
- OSTI Identifier:
- 1388395
- Grant/Contract Number:
- SC0001299; FG02-09ER46577; SC0014520; AC02-06CH11357
- Resource Type:
- Accepted Manuscript
- Journal Name:
- Chemistry of Materials
- Additional Journal Information:
- Journal Volume: 29; Journal Issue: 3; Related Information: S3TEC partners with Massachusetts Institute of Technology (lead); Boston College; Oak Ridge National Laboratory; Rensselaer Polytechnic Institute; Journal ID: ISSN 0897-4756
- Publisher:
- American Chemical Society (ACS)
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 36 MATERIALS SCIENCE; solar (photovoltaic); solar (thermal); solid state lighting; phonons; thermal conductivity; thermoelectric, defects; mechanical behavior; charge transport; spin dynamics; materials and chemistry by design; optics; synthesis (novel materials); synthesis (self-assembly); synthesis (scalable processing)
Citation Formats
Zeier, Wolfgang G., Anand, Shashwat, Huang, Lihong, He, Ran, Zhang, Hao, Ren, Zhifeng, Wolverton, Chris, and Snyder, G. Jeffrey. Using the 18-Electron Rule To Understand the Nominal 19-Electron Half-Heusler NbCoSb with Nb Vacancies. United States: N. p., 2017.
Web. doi:10.1021/acs.chemmater.6b04583.
Zeier, Wolfgang G., Anand, Shashwat, Huang, Lihong, He, Ran, Zhang, Hao, Ren, Zhifeng, Wolverton, Chris, & Snyder, G. Jeffrey. Using the 18-Electron Rule To Understand the Nominal 19-Electron Half-Heusler NbCoSb with Nb Vacancies. United States. https://doi.org/10.1021/acs.chemmater.6b04583
Zeier, Wolfgang G., Anand, Shashwat, Huang, Lihong, He, Ran, Zhang, Hao, Ren, Zhifeng, Wolverton, Chris, and Snyder, G. Jeffrey. Tue .
"Using the 18-Electron Rule To Understand the Nominal 19-Electron Half-Heusler NbCoSb with Nb Vacancies". United States. https://doi.org/10.1021/acs.chemmater.6b04583. https://www.osti.gov/servlets/purl/1388395.
@article{osti_1388395,
title = {Using the 18-Electron Rule To Understand the Nominal 19-Electron Half-Heusler NbCoSb with Nb Vacancies},
author = {Zeier, Wolfgang G. and Anand, Shashwat and Huang, Lihong and He, Ran and Zhang, Hao and Ren, Zhifeng and Wolverton, Chris and Snyder, G. Jeffrey},
abstractNote = {The 18-electron rule is a widely used criterion in the search for new half-Heusler thermoelectric materials. However, several 19-electron compounds such as NbCoSb have been found to be stable and exhibit thermoelectric properties rivaling state-of-the art materials. Using synchrotron X-ray diffraction and density functional theory calculations, we show that samples with nominal (19-electron) composition NbCoSb actually contain a half-Heusler phase with composition Nb0.84CoSb. The large amount of stable Nb vacancies reduces the overall electron count, which brings the stoichiometry of the compound close to an 18-electron count, and stabilizes the material. Excess electrons beyond 18 electrons provide heavy doping needed to make these good thermoelectric materials. This work demonstrates that considering possible defect chemistry and allowing small variation of electron counting leads to extra degrees of freedom for tailoring thermoelectric properties and exploring new compounds. Here we discuss the 18-electron rule as a guide to find defect-free half-Heusler semiconductors. As a result, other electron counts such as 19-electron NbCoSb can also be expected to be stable as n-type metals, perhaps with cation vacancy defects to reduce the electron count.},
doi = {10.1021/acs.chemmater.6b04583},
journal = {Chemistry of Materials},
number = 3,
volume = 29,
place = {United States},
year = {Tue Jan 17 00:00:00 EST 2017},
month = {Tue Jan 17 00:00:00 EST 2017}
}
Web of Science
Works referenced in this record:
Complex thermoelectric materials
journal, February 2008
- Snyder, G. Jeffrey; Toberer, Eric S.
- Nature Materials, Vol. 7, Issue 2, p. 105-114
Rapid Microwave Preparation of Thermoelectric TiNiSn and TiCoSb Half-Heusler Compounds
journal, June 2012
- Birkel, Christina S.; Zeier, Wolfgang G.; Douglas, Jason E.
- Chemistry of Materials, Vol. 24, Issue 13
Recent progress of half-Heusler for moderate temperature thermoelectric applications
journal, October 2013
- Chen, Shuo; Ren, Zhifeng
- Materials Today, Vol. 16, Issue 10
Nanoscale structural heterogeneity in Ni-rich half-Heusler TiNiSn
journal, October 2014
- Douglas, Jason E.; Chater, Philip A.; Brown, Craig M.
- Journal of Applied Physics, Vol. 116, Issue 16
Compositions and thermoelectric properties of XNiSn (X = Ti, Zr, Hf) half-Heusler alloys
journal, January 2015
- Downie, R. A.; Barczak, S. A.; Smith, R. I.
- Journal of Materials Chemistry C, Vol. 3, Issue 40
Metal Distributions, Efficient n-Type Doping, and Evidence for in-Gap States in TiNiM y Sn (M = Co, Ni, Cu) half-Heusler Nanocomposites
journal, March 2015
- Downie, Ruth A.; Smith, Ronald I.; MacLaren, Donald A.
- Chemistry of Materials, Vol. 27, Issue 7
Recent progress in half-Heusler thermoelectric materials
journal, April 2016
- Huang, Lihong; Zhang, Qinyong; Yuan, Bo
- Materials Research Bulletin, Vol. 76
Electronic structure and optical, mechanical, and transport properties of the pure, electron-doped, and hole-doped Heusler compound CoTiSb
journal, July 2012
- Ouardi, Siham; Fecher, Gerhard H.; Felser, Claudia
- Physical Review B, Vol. 86, Issue 4
Charge carrier concentration optimization of thermoelectric p -type half-Heusler compounds
journal, April 2015
- Rausch, Elisabeth; Balke, Benjamin; Deschauer, Torben
- APL Materials, Vol. 3, Issue 4
The intrinsic disorder related alloy scattering in ZrNiSn half-Heusler thermoelectric materials
journal, November 2014
- Xie, Hanhui; Wang, Heng; Fu, Chenguang
- Scientific Reports, Vol. 4, Issue 1
Evaluation of Half-Heusler Compounds as Thermoelectric Materials Based on the Calculated Electrical Transport Properties
journal, October 2008
- Yang, Jiong; Li, Huanming; Wu, Ting
- Advanced Functional Materials, Vol. 18, Issue 19, p. 2880-2888
Enhancement in Thermoelectric Figure-Of-Merit of an N-Type Half-Heusler Compound by the Nanocomposite Approach
journal, May 2011
- Joshi, Giri; Yan, Xiao; Wang, Hengzhi
- Advanced Energy Materials, Vol. 1, Issue 4, p. 643-647
Thermoelectric performance of nanostructured p-type Zr0.5Hf0.5Co0.4Rh0.6Sb1−xSnx half-Heusler alloys
journal, June 2013
- Maji, Pramathesh; Makongo, Julien P. A.; Zhou, Xiaoyuan
- Journal of Solid State Chemistry, Vol. 202
Simultaneous Large Enhancements in Thermopower and Electrical Conductivity of Bulk Nanostructured Half-Heusler Alloys
journal, November 2011
- Makongo, Julien P. A.; Misra, Dinesh K.; Zhou, Xiaoyuan
- Journal of the American Chemical Society, Vol. 133, Issue 46
Recent Advances in Nanostructured Thermoelectric Half-Heusler Compounds
journal, November 2012
- Xie, Wenjie; Weidenkaff, Anke; Tang, Xinfeng
- Nanomaterials, Vol. 2, Issue 4
Large Enhancements of Thermopower and Carrier Mobility in Quantum Dot Engineered Bulk Semiconductors
journal, May 2013
- Liu, Yuanfeng; Sahoo, Pranati; Makongo, Julien P. A.
- Journal of the American Chemical Society, Vol. 135, Issue 20
Thermoelectric Property Study of Nanostructured p-Type Half-Heuslers (Hf, Zr, Ti)CoSb 0.8 Sn 0.2
journal, May 2013
- Yan, Xiao; Liu, Weishu; Chen, Shuo
- Advanced Energy Materials, Vol. 3, Issue 9
Stronger phonon scattering by larger differences in atomic mass and size in p-type half-Heuslers Hf1−xTixCoSb0.8Sn0.2
journal, January 2012
- Yan, Xiao; Liu, Weishu; Wang, Hui
- Energy & Environmental Science, Vol. 5, Issue 6, p. 7543-7548
Beneficial Contribution of Alloy Disorder to Electron and Phonon Transport in Half-Heusler Thermoelectric Materials
journal, April 2013
- Xie, Hanhui; Wang, Heng; Pei, Yanzhong
- Advanced Functional Materials, Vol. 23, Issue 41
Engineering half-Heusler thermoelectric materials using Zintl chemistry
journal, May 2016
- Zeier, Wolfgang G.; Schmitt, Jennifer; Hautier, Geoffroy
- Nature Reviews Materials, Vol. 1, Issue 6
High Efficiency Half-Heusler Thermoelectric Materials for Energy Harvesting
journal, July 2015
- Zhu, Tiejun; Fu, Chenguang; Xie, Hanhui
- Advanced Energy Materials, Vol. 5, Issue 19
Band engineering of high performance p-type FeNbSb based half-Heusler thermoelectric materials for figure of merit zT > 1
journal, January 2015
- Fu, Chenguang; Zhu, Tiejun; Liu, Yintu
- Energy & Environmental Science, Vol. 8, Issue 1
Simple rules for the understanding of Heusler compounds
journal, May 2011
- Graf, Tanja; Felser, Claudia; Parkin, Stuart S. P.
- Progress in Solid State Chemistry, Vol. 39, Issue 1
(Zr,Hf)Co(Sb,Sn) half-Heusler phases as high-temperature (>700°C) p-type thermoelectric materials
journal, July 2008
- Culp, Slade R.; Simonson, J. W.; Poon, S. Joseph
- Applied Physics Letters, Vol. 93, Issue 2
A new n-type half-Heusler thermoelectric material NbCoSb
journal, October 2015
- Huang, Lihong; He, Ran; Chen, Shuo
- Materials Research Bulletin, Vol. 70
Synthesis and thermoelectric properties of n-type half-Heusler compound VCoSb with valence electron count of 19
journal, January 2016
- Zhang, Hao; Wang, Yumei; Huang, Lihong
- Journal of Alloys and Compounds, Vol. 654
Thinking Like a Chemist: Intuition in Thermoelectric Materials
journal, April 2016
- Zeier, Wolfgang G.; Zevalkink, Alex; Gibbs, Zachary M.
- Angewandte Chemie International Edition, Vol. 55, Issue 24
Recent advances in magnetic structure determination by neutron powder diffraction
journal, October 1993
- Rodríguez-Carvajal, Juan
- Physica B: Condensed Matter, Vol. 192, Issue 1-2
Density Functional Theory of Electronic Structure
journal, January 1996
- Kohn, W.; Becke, A. D.; Parr, R. G.
- The Journal of Physical Chemistry, Vol. 100, Issue 31
Ab initio molecular-dynamics simulation of the liquid-metal–amorphous-semiconductor transition in germanium
journal, May 1994
- Kresse, G.; Hafner, J.
- Physical Review B, Vol. 49, Issue 20, p. 14251-14269
Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set
journal, October 1996
- Kresse, G.; Furthmüller, J.
- Physical Review B, Vol. 54, Issue 16, p. 11169-11186
From ultrasoft pseudopotentials to the projector augmented-wave method
journal, January 1999
- Kresse, G.; Joubert, D.
- Physical Review B, Vol. 59, Issue 3, p. 1758-1775
Projector augmented-wave method
journal, December 1994
- Blöchl, P. E.
- Physical Review B, Vol. 50, Issue 24, p. 17953-17979
Generalized Gradient Approximation Made Simple
journal, October 1996
- Perdew, John P.; Burke, Kieron; Ernzerhof, Matthias
- Physical Review Letters, Vol. 77, Issue 18, p. 3865-3868
The Open Quantum Materials Database (OQMD): assessing the accuracy of DFT formation energies
journal, December 2015
- Kirklin, Scott; Saal, James E.; Meredig, Bryce
- npj Computational Materials, Vol. 1, Issue 1
Materials Design and Discovery with High-Throughput Density Functional Theory: The Open Quantum Materials Database (OQMD)
journal, September 2013
- Saal, James E.; Kirklin, Scott; Aykol, Muratahan
- JOM, Vol. 65, Issue 11
The alloy theoretic automated toolkit: A user guide
journal, December 2002
- van de Walle, A.; Asta, M.; Ceder, G.
- Calphad, Vol. 26, Issue 4
Automating first-principles phase diagram calculations
journal, August 2002
- Walle, A.; Ceder, G.
- Journal of Phase Equilibria, Vol. 23, Issue 4
Synthesis and characterization of Fe-Ti-Sb intermetallic compounds: Discovery of a new Slater-Pauling phase
journal, March 2016
- Naghibolashrafi, N.; Keshavarz, S.; Hegde, Vinay I.
- Physical Review B, Vol. 93, Issue 10
Nonstoichiometry in the Zintl Phase Yb 1−δ Zn 2 Sb 2 as a Route to Thermoelectric Optimization
journal, September 2014
- Zevalkink, Alex; Zeier, Wolfgang G.; Cheng, Ethan
- Chemistry of Materials, Vol. 26, Issue 19
In-gap Electronic States Responsible for the Excellent Thermoelectric Properties of Ni-based Half-Heusler Alloys
journal, July 2008
- Miyamoto, Koji; Kimura, Akio; Sakamoto, Kazuaki
- Applied Physics Express, Vol. 1
Electronic and Local Crystal Structures of the ZrNiSn Half-Heusler Thermoelectric Material
journal, January 2014
- Miyazaki, Hidetoshi; Nakano, Teruaki; Inukai, Manabu
- MATERIALS TRANSACTIONS, Vol. 55, Issue 8
Direct observation of the electronic structure in thermoelectric half-Heusler alloys Zr 1− x M x NiSn ( M = Y and Nb)
journal, May 2015
- Hattori, Kengo; Miyazaki, Hidetoshi; Yoshida, Kento
- Journal of Applied Physics, Vol. 117, Issue 20
Interrelation between atomic switching disorder and thermoelectric properties of ZrNiSn half-Heusler compounds
journal, January 2012
- Xie, Han-Hui; Mi, Jian-Li; Hu, Li-Peng
- CrystEngComm, Vol. 14, Issue 13
Special quasirandom structures
journal, July 1990
- Zunger, Alex; Wei, S.-H.; Ferreira, L. G.
- Physical Review Letters, Vol. 65, Issue 3, p. 353-356
Unfolding spinor wave functions and expectation values of general operators: Introducing the unfolding-density operator
journal, January 2015
- Medeiros, Paulo V. C.; Tsirkin, Stepan S.; Stafström, Sven
- Physical Review B, Vol. 91, Issue 4
Effects of extrinsic and intrinsic perturbations on the electronic structure of graphene: Retaining an effective primitive cell band structure by band unfolding
journal, January 2014
- Medeiros, Paulo V. C.; Stafström, Sven; Björk, Jonas
- Physical Review B, Vol. 89, Issue 4
Extracting versus effective band structure from supercell calculations on alloys and impurities
journal, February 2012
- Popescu, Voicu; Zunger, Alex
- Physical Review B, Vol. 85, Issue 8
High Thermoelectric Performance SnTe–In 2 Te 3 Solid Solutions Enabled by Resonant Levels and Strong Vacancy Phonon Scattering
journal, November 2015
- Tan, Gangjian; Zeier, Wolfgang G.; Shi, Fengyuan
- Chemistry of Materials, Vol. 27, Issue 22
Influence of Compensating Defect Formation on the Doping Efficiency and Thermoelectric Properties of Cu 2-y Se 1– x Br x
journal, October 2015
- Day, Tristan W.; Weldert, Kai S.; Zeier, Wolfgang G.
- Chemistry of Materials, Vol. 27, Issue 20
Determining conductivity and mobility values of individual components in multiphase composite Cu 1.97 Ag 0.03 Se
journal, October 2014
- Day, Tristan W.; Zeier, Wolfgang G.; Brown, David R.
- Applied Physics Letters, Vol. 105, Issue 17
Works referencing / citing this record:
Temperature Dependent n-Type Self Doping in Nominally 19-Electron Half-Heusler Thermoelectric Materials
journal, September 2018
- Anand, Shashwat; Xia, Kaiyang; Zhu, Tiejun
- Advanced Energy Materials, Vol. 8, Issue 30
The Effects of Excess Co on the Phase Composition and Thermoelectric Properties of Half-Heusler NbCoSb
journal, May 2018
- Huang, Lihong; Wang, Junchen; Chen, Xi
- Materials, Vol. 11, Issue 5
Design of High‐Performance Disordered Half‐Heusler Thermoelectric Materials Using 18‐Electron Rule
journal, August 2019
- Liu, Zihang; Guo, Shuping; Wu, Yixuan
- Advanced Functional Materials, Vol. 29, Issue 44
Impact of Nb vacancies and p-type doping of the NbCoSn–NbCoSb half-Heusler thermoelectrics
journal, January 2018
- Ferluccio, Daniella A.; Smith, Ronald I.; Buckman, Jim
- Physical Chemistry Chemical Physics, Vol. 20, Issue 6
Band Structures and Transport Properties of High-Performance Half-Heusler Thermoelectric Materials by First Principles
journal, May 2018
- Fang, Teng; Zhao, Xinbing; Zhu, Tiejun
- Materials, Vol. 11, Issue 5
Low thermal conductivity and promising thermoelectric performance in A x CoSb (A = V, Nb or Ta) half-Heuslers with inherent vacancies
journal, January 2019
- Ferluccio, Daniella A.; Halpin, John E.; MacIntosh, Kathryn L.
- Journal of Materials Chemistry C, Vol. 7, Issue 22
A valence balanced rule for discovery of 18-electron half-Heuslers with defects
journal, January 2018
- Anand, Shashwat; Xia, Kaiyang; I. Hegde, Vinay
- Energy & Environmental Science, Vol. 11, Issue 6
Improving the Thermoelectric Properties of the Half-Heusler Compound VCoSb by Vanadium Vacancy
journal, May 2019
- Huang, Lihong; Wang, Junchen; Mo, Xiaobo
- Materials, Vol. 12, Issue 10
Enhanced Thermoelectric Performance in 18-Electron Nb 0.8 CoSb Half-Heusler Compound with Intrinsic Nb Vacancies
journal, January 2018
- Xia, Kaiyang; Liu, Yintu; Anand, Shashwat
- Advanced Functional Materials, Vol. 28, Issue 9
Short-range order in defective half-Heusler thermoelectric crystals
journal, January 2019
- Xia, Kaiyang; Nan, Pengfei; Tan, Shihua
- Energy & Environmental Science, Vol. 12, Issue 5
Vacancy and anti-site disorder scattering in AgBiSe 2 thermoelectrics
journal, January 2017
- Böcher, Felix; Culver, Sean P.; Peilstöcker, Jan
- Dalton Transactions, Vol. 46, Issue 12
High performance p-type half-Heusler thermoelectric materials
journal, February 2018
- Yu, Junjie; Xia, Kaiyang; Zhao, Xinbing
- Journal of Physics D: Applied Physics, Vol. 51, Issue 11
The Effects of Excess Co on the Phase Composition and Thermoelectric Properties of Half-Heusler NbCoSb
journal, May 2018
- Huang, Lihong; Wang, Junchen; Chen, Xi
- Materials, Vol. 11, Issue 5
Band Structures and Transport Properties of High-Performance Half-Heusler Thermoelectric Materials by First Principles
journal, May 2018
- Fang, Teng; Zhao, Xinbing; Zhu, Tiejun
- Materials, Vol. 11, Issue 5
Improving the Thermoelectric Properties of the Half-Heusler Compound VCoSb by Vanadium Vacancy
journal, May 2019
- Huang, Lihong; Wang, Junchen; Mo, Xiaobo
- Materials, Vol. 12, Issue 10