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Woods-Robinson R, Horton MK, Persson KA. A method to computationally screen for tunable properties of crystalline alloys. Patterns (N Y) 2023; 4:100723. [PMID: 37223274 PMCID: PMC10201207 DOI: 10.1016/j.patter.2023.100723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 12/19/2022] [Accepted: 03/08/2023] [Indexed: 05/25/2023]
Abstract
Conventionally, high-throughput computational materials searches start from an input set of bulk compounds extracted from material databases, but, in contrast, many real functional materials are heavily engineered mixtures of compounds rather than single bulk compounds. We present a framework and open-source code to automatically construct and analyze possible alloys and solid solutions from a set of existing experimental or calculated ordered compounds, without requiring additional metadata except crystal structure. As a demonstration, we apply this framework to all compounds in the Materials Project to create a new, publicly available database of > 600,000 unique "alloy pair" entries that can be used to search for materials with tunable properties. We exemplify this approach by searching for transparent conductors and reveal candidates that might have been excluded in a traditional screening. This work lays a foundation from which materials databases can go beyond stoichiometric compounds and approach a more realistic description of compositionally tunable materials.
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Affiliation(s)
- Rachel Woods-Robinson
- Applied Science and Technology Graduate Group, University of California at Berkeley, Berkeley, CA 94720, USA
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Matthew K. Horton
- Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Kristin A. Persson
- Department of Materials Science and Engineering, University of California at Berkeley, Berkeley, CA 94720, USA
- Molecular Foundry Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
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2
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Bordoloi AD, Scheidweiler D, Dentz M, Bouabdellaoui M, Abbarchi M, de Anna P. Structure induced laminar vortices control anomalous dispersion in porous media. Nat Commun 2022; 13:3820. [PMID: 35780187 DOI: 10.1038/s41467-022-31552-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 06/20/2022] [Indexed: 11/08/2022] Open
Abstract
Natural porous systems, such as soil, membranes, and biological tissues comprise disordered structures characterized by dead-end pores connected to a network of percolating channels. The release and dispersion of particles, solutes, and microorganisms from such features is key for a broad range of environmental and medical applications including soil remediation, filtration and drug delivery. Yet, owing to the stagnant and opaque nature of these disordered systems, the role of microscopic structure and flow on the dispersion of particles and solutes remains poorly understood. Here, we use a microfluidic model system that features a pore structure characterized by distributed dead-ends to determine how particles are transported, retained and dispersed. We observe strong tailing of arrival time distributions at the outlet of the medium characterized by power-law decay with an exponent of 2/3. Using numerical simulations and an analytical model, we link this behavior to particles initially located within dead-end pores, and explain the tailing exponent with a hopping across and rolling along the streamlines of vortices within dead-end pores. We quantify such anomalous dispersal by a stochastic model that predicts the full evolution of arrival times. Our results demonstrate how microscopic flow structures can impact macroscopic particle transport.
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3
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Cavin J, Mishra R. Equilibrium phase diagrams of isostructural and heterostructural two-dimensional alloys from first principles. iScience 2022; 25:104161. [PMID: 35434554 PMCID: PMC9010766 DOI: 10.1016/j.isci.2022.104161] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 02/28/2022] [Accepted: 03/23/2022] [Indexed: 11/26/2022] Open
Abstract
Alloying is a successful strategy for tuning the phases and properties of two-dimensional (2D) transition metal dichalcogenides (TMDCs). To accelerate the synthesis of TMDC alloys, we present a method for generating temperature-composition equilibrium phase diagrams by combining first-principles total-energy calculations with thermodynamic solution models. This method is applied to three representative 2D TMDC alloys: an isostructural alloy, MoS2(1-x)Te2x , and two heterostructural alloys, Mo1-x W x Te2 and WS2(1-x)Te2x . Using density-functional theory and special quasi-random structures, we show that the mixing enthalpy of these binary alloys can be reliably represented using a sub-regular solution model fitted to the total energies of relatively few compositions. The cubic sub-regular solution model captures 3-body effects that are important in TMDC alloys. By comparing phase diagrams generated with this method to those calculated with previous methods, we demonstrate that this method can be used to rapidly design phase diagrams of TMDC alloys and related 2D materials.
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Affiliation(s)
- John Cavin
- Department of Physics, Washington University in St. Louis, St. Louis, MO 63130, USA
| | - Rohan Mishra
- Department of Mechanical Engineering and Material Science, and Institute of Materials Science and Engineering, Washington University in St. Louis, St. Louis, MO 63130, USA
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4
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Abstract
Two-dimensional (2D) materials exhibit a wide range of atomic structures, compositions, and associated versatility of properties. Furthermore, for a given composition, a variety of different crystal structures (i.e., polymorphs) can be observed. Polymorphism in 2D materials presents a fertile landscape for designing novel architectures and imparting new functionalities. The objective of this Review is to identify the polymorphs of emerging 2D materials, describe their polymorph-dependent properties, and outline methods used for polymorph control. Since traditional 2D materials (e.g., graphene, hexagonal boron nitride, and transition metal dichalcogenides) have already been studied extensively, the focus here is on polymorphism in post-dichalcogenide 2D materials including group III, IV, and V elemental 2D materials, layered group III, IV, and V metal chalcogenides, and 2D transition metal halides. In addition to providing a comprehensive survey of recent experimental and theoretical literature, this Review identifies the most promising opportunities for future research including how 2D polymorph engineering can provide a pathway to materials by design.
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Affiliation(s)
- Hadallia Bergeron
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Dmitry Lebedev
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
| | - Mark C Hersam
- Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States.,Department of Chemistry, Northwestern University, Evanston, Illinois 60208, United States.,Department of Electrical and Computer Engineering, Northwestern University, Evanston, Illinois 60208, United States
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5
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Noor-A-Alam M, Olszewski OZ, Campanella H, Nolan M. Large Piezoelectric Response and Ferroelectricity in Li and V/Nb/Ta Co-Doped w-AlN. ACS Appl Mater Interfaces 2021; 13:944-954. [PMID: 33382599 DOI: 10.1021/acsami.0c19620] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Enhancement of piezoelectricity in w-AlN is desired for many devices including resonators for next-generation wireless communication systems, sensors, and vibrational energy harvesters. Based on density functional theory, we show that Li and X (X = V, Nb, and Ta) co-doping in 1Li:1X ratio transforms brittle w-AlN crystal to ductile, along with broadening the compositional freedom for significantly enhanced piezoelectric response, promising them to be good alternatives to expensive Sc. Interestingly, these co-doped w-AlN also show quite large spontaneous electric polarization (e.g., about 1 C/m2 for Li0.125X0.125Al0.75N) with the possibility of ferroelectric polarization switching, opening new possibilities in wurtzite nitrides. An increase in piezoelectric stress constant (e33) with a decrease in elastic constant (C33) results in an enhancement of piezoelectric strain constant (d33), which is desired for improving the performance of bulk acoustic wave (BAW) resonators for high-frequency radio frequency (RF) signals. Also, these co-doped w-AlN are potential lead-free piezoelectric materials for energy harvesting and sensors as they improve the longitudinal electromechanical coupling constant (K332), transverse piezoelectric strain constant (d31), and figure of merit (FOM) for power generation. However, the enhancement in K332 is not as pronounced as that in d33 because co-doping increases dielectric constant. The longitudinal acoustic wave velocity (7.09 km/s) of Li0.1875Ta0.1875Al0.625N is quite comparable to that of commercially used piezoelectric LiNbO3 or LiTaO3 in special cuts (about 5-7 km/s) despite the fact that the acoustic wave velocities, important parameters for designing resonators or sensors, decrease with co-doping or Sc concentration.
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Affiliation(s)
- Mohammad Noor-A-Alam
- Tyndall National Institute, Lee Maltings, Dyke Parade, University College Cork, Cork T12 R5CP, Ireland
| | - Oskar Z Olszewski
- Tyndall National Institute, Lee Maltings, Dyke Parade, University College Cork, Cork T12 R5CP, Ireland
| | - Humberto Campanella
- Tyndall National Institute, Lee Maltings, Dyke Parade, University College Cork, Cork T12 R5CP, Ireland
| | - Michael Nolan
- Tyndall National Institute, Lee Maltings, Dyke Parade, University College Cork, Cork T12 R5CP, Ireland
- NIBEC, School of Engineering, Ulster University, Shore Road, Antrim BT37 0QB, Northern Ireland
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6
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Kim H, Schreuders H, Sakaki K, Asano K, Nakamura Y, Maejima N, Machida A, Watanuki T, Dam B. Unveiling Nanoscale Compositional and Structural Heterogeneities of Highly Textured Mg 0.7Ti 0.3H y Thin Films. Inorg Chem 2020; 59:6800-6807. [PMID: 32379436 DOI: 10.1021/acs.inorgchem.0c00059] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Thin films often exhibit fascinating properties, but the understanding of the underlying mechanism behind such properties is not simple. This is partially because of the limited structural information available. The hurdle in obtaining such information is especially high for textured thin films such as Mg-rich MgxTi1-x, a promising switchable smart coating material. Although these metastable thin films are seen as solid solution alloys by conventional crystallographic methods, their hydrogen-induced optical transition is hardly understood by a solid solution model. In this study, we collect atomic pair distribution function (PDF) data for a Mg0.7Ti0.3Hy thin film in situ on hydrogenation and successfully resolve TiH2 clusters of an average size of 30 Å embedded in the Mg matrix. This supports the chemically segregated model previously proposed for this system. We also observe the emergence of a previously unknown intermediate face-centered tetragonal phase during hydrogenation of the Mg matrix. This phase appears between Mg and MgH2 to reduce lattice mismatch, thereby preventing pulverization and facilitating rapid hydrogen uptake. This work may shed new light on the hydrogen-induced properties of Mg-rich MgxTi1-x thin films.
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Affiliation(s)
- Hyunjeong Kim
- National Institute of Advanced Industrial Science and Technology, 16-1 Onogawa, Tsukuba, Ibaraki 305-8569, Japan
| | - Herman Schreuders
- Department of Chemical Engineering, MECS, Delft University of Technology, Van der Maaslaan 9, 2629 HZ Delft, The Netherlands
| | - Kouji Sakaki
- National Institute of Advanced Industrial Science and Technology, 16-1 Onogawa, Tsukuba, Ibaraki 305-8569, Japan
| | - Kohta Asano
- National Institute of Advanced Industrial Science and Technology, 16-1 Onogawa, Tsukuba, Ibaraki 305-8569, Japan
| | - Yumiko Nakamura
- National Institute of Advanced Industrial Science and Technology, 16-1 Onogawa, Tsukuba, Ibaraki 305-8569, Japan
| | - Naoyuki Maejima
- Department of Chemistry, Rikkyo University, 3-34-1 Nishiikebukuro, Toshima-ku, Tokyo 171-8501, Japan
| | - Akihiko Machida
- National Institutes for Quantum and Radiological Science and Technology, 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan
| | - Tetsu Watanuki
- National Institutes for Quantum and Radiological Science and Technology, 1-1-1 Kouto, Sayo, Hyogo 679-5148, Japan
| | - Bernard Dam
- Department of Chemical Engineering, MECS, Delft University of Technology, Van der Maaslaan 9, 2629 HZ Delft, The Netherlands
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7
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Ndione PF, Ratcliff EL, Dey SR, Warren EL, Peng H, Holder AM, Lany S, Gorman BP, Al-Jassim MM, Deutsch TG, Zakutayev A, Ginley DS. High-Throughput Experimental Study of Wurtzite Mn 1-x Zn x O Alloys for Water Splitting Applications. ACS Omega 2019; 4:7436-7447. [PMID: 31459840 PMCID: PMC6648451 DOI: 10.1021/acsomega.8b03347] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 04/02/2019] [Indexed: 05/31/2023]
Abstract
We used high-throughput experimental screening methods to unveil the physical and chemical properties of Mn1-x Zn x O wurtzite alloys and identify their appropriate composition for effective water splitting application. The Mn1-x Zn x O thin films were synthesized using combinatorial pulsed laser deposition, permitting for characterization of a wide range of compositions with x varying from 0 to 1. The solubility limit of ZnO in MnO was determined using the disappearing phase method from X-ray diffraction and X-ray fluorescence data and found to increase with decreasing substrate temperature due to kinetic limitations of the thin-film growth at relatively low temperature. Optical measurements indicate the strong reduction of the optical band gap down to 2.1 eV at x = 0.5 associated with the rock salt-to-wurtzite structural transition in Mn1-x Zn x O alloys. Transmission electron microscopy results show evidence of a homogeneous wurtzite alloy system for a broad range of Mn1-x Zn x O compositions above x = 0.4. The wurtzite Mn1-x ZnxO samples with the 0.4 < x < 0.6 range were studied as anodes for photoelectrochemical water splitting, with a maximum current density of 340 μA cm-2 for 673 nm-thick films. These Mn1-x Zn x O films were stable in pH = 10, showing no evidence of photocorrosion or degradation after 24 h under water oxidation conditions. Doping Mn1-x Zn x O materials with Ga dramatically increases the electrical conductivity of Mn1-x Zn x O up to ∼1.9 S/cm for x = 0.48, but these doped samples are not active in water splitting. Mott-Schottky and UPS/XPS measurements show that the presence of dopant atoms reduces the space charge region and increases the number of mid-gap surface states. Overall, this study demonstrates that Mn1-x Zn x O alloys hold promise for photoelectrochemical water splitting, which could be enhanced with further tailoring of their electronic properties.
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Affiliation(s)
- Paul F. Ndione
- Materials
Science Center, National Renewable Energy
Laboratory, Golden, Colorado 80401, United States
| | - Erin L. Ratcliff
- Department
of Materials Science and Engineering, The
University of Arizona, Tucson, Arizona 85721, United States
| | - Suhash R. Dey
- Department
of Materials Science and Metallurgical Engineering, Indian Institute of Technology Hyderabad, Kandi, Sangareddy, Hyderabad 502285, India
| | - Emily L. Warren
- Materials
Science Center, National Renewable Energy
Laboratory, Golden, Colorado 80401, United States
| | - Haowei Peng
- Materials
Science Center, National Renewable Energy
Laboratory, Golden, Colorado 80401, United States
| | - Aaron M. Holder
- Materials
Science Center, National Renewable Energy
Laboratory, Golden, Colorado 80401, United States
| | - Stephan Lany
- Materials
Science Center, National Renewable Energy
Laboratory, Golden, Colorado 80401, United States
| | - Brian P. Gorman
- Materials
Science Center, National Renewable Energy
Laboratory, Golden, Colorado 80401, United States
- Department
of Metallurgical and Materials Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
| | - Mowafak M. Al-Jassim
- Materials
Science Center, National Renewable Energy
Laboratory, Golden, Colorado 80401, United States
| | - Todd G. Deutsch
- Materials
Science Center, National Renewable Energy
Laboratory, Golden, Colorado 80401, United States
| | - Andriy Zakutayev
- Materials
Science Center, National Renewable Energy
Laboratory, Golden, Colorado 80401, United States
| | - David S. Ginley
- Materials
Science Center, National Renewable Energy
Laboratory, Golden, Colorado 80401, United States
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8
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Affiliation(s)
- Albert V Davydov
- Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Ursula R Kattner
- Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, MD, USA
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9
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Bartel CJ, Millican SL, Deml AM, Rumptz JR, Tumas W, Weimer AW, Lany S, Stevanović V, Musgrave CB, Holder AM. Physical descriptor for the Gibbs energy of inorganic crystalline solids and temperature-dependent materials chemistry. Nat Commun 2018; 9:4168. [PMID: 30301890 PMCID: PMC6177451 DOI: 10.1038/s41467-018-06682-4] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 09/19/2018] [Indexed: 11/21/2022] Open
Abstract
The Gibbs energy, G, determines the equilibrium conditions of chemical reactions and materials stability. Despite this fundamental and ubiquitous role, G has been tabulated for only a small fraction of known inorganic compounds, impeding a comprehensive perspective on the effects of temperature and composition on materials stability and synthesizability. Here, we use the SISSO (sure independence screening and sparsifying operator) approach to identify a simple and accurate descriptor to predict G for stoichiometric inorganic compounds with ~50 meV atom-1 (~1 kcal mol-1) resolution, and with minimal computational cost, for temperatures ranging from 300-1800 K. We then apply this descriptor to ~30,000 known materials curated from the Inorganic Crystal Structure Database (ICSD). Using the resulting predicted thermochemical data, we generate thousands of temperature-dependent phase diagrams to provide insights into the effects of temperature and composition on materials synthesizability and stability and to establish the temperature-dependent scale of metastability for inorganic compounds.
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Affiliation(s)
- Christopher J Bartel
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO, 80309, USA
| | - Samantha L Millican
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO, 80309, USA
| | - Ann M Deml
- Department of Metallurgical and Materials Engineering, Colorado School of Mines, Golden, CO, 80401, USA
- National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - John R Rumptz
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO, 80309, USA
| | - William Tumas
- National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Alan W Weimer
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO, 80309, USA
| | - Stephan Lany
- National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Vladan Stevanović
- Department of Metallurgical and Materials Engineering, Colorado School of Mines, Golden, CO, 80401, USA
- National Renewable Energy Laboratory, Golden, CO, 80401, USA
| | - Charles B Musgrave
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO, 80309, USA.
- National Renewable Energy Laboratory, Golden, CO, 80401, USA.
- Department of Chemistry and Biochemistry, University of Colorado, Boulder, CO, 80309, USA.
| | - Aaron M Holder
- Department of Chemical and Biological Engineering, University of Colorado, Boulder, CO, 80309, USA.
- National Renewable Energy Laboratory, Golden, CO, 80401, USA.
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10
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Siol S, Holder A, Steffes J, Schelhas LT, Stone KH, Garten L, Perkins JD, Parilla PA, Toney MF, Huey BD, Tumas W, Lany S, Zakutayev A. Negative-pressure polymorphs made by heterostructural alloying. Sci Adv 2018; 4:eaaq1442. [PMID: 29725620 PMCID: PMC5930396 DOI: 10.1126/sciadv.aaq1442] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 03/07/2018] [Indexed: 06/01/2023]
Abstract
The ability of a material to adopt multiple structures, known as polymorphism, is a fascinating natural phenomenon. Various polymorphs with unusual properties are routinely synthesized by compression under positive pressure. However, changing a material's structure by applying tension under negative pressure is much more difficult. We show how negative-pressure polymorphs can be synthesized by mixing materials with different crystal structures-a general approach that should be applicable to many materials. Theoretical calculations suggest that it costs less energy to mix low-density structures than high-density structures, due to less competition for space between the atoms. Proof-of-concept experiments confirm that mixing two different high-density forms of MnSe and MnTe stabilizes a Mn(Se,Te) alloy with a low-density wurtzite structure. This Mn(Se,Te) negative-pressure polymorph has 2× to 4× lower electron effective mass compared to MnSe and MnTe parent compounds and has a piezoelectric response that none of the parent compounds have. This example shows how heterostructural alloying can lead to negative-pressure polymorphs with useful properties-materials that are otherwise nearly impossible to make.
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Affiliation(s)
- Sebastian Siol
- National Renewable Energy Laboratory, Golden, CO 80401, USA
| | - Aaron Holder
- National Renewable Energy Laboratory, Golden, CO 80401, USA
- University of Colorado, Boulder, CO 80309, USA
| | | | | | - Kevin H. Stone
- SLAC National Accelerator Laboratory, Menlo Park, CA 94025, USA
| | - Lauren Garten
- National Renewable Energy Laboratory, Golden, CO 80401, USA
| | | | | | | | | | - William Tumas
- National Renewable Energy Laboratory, Golden, CO 80401, USA
| | - Stephan Lany
- National Renewable Energy Laboratory, Golden, CO 80401, USA
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11
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Arca E, Lany S, Perkins JD, Bartel C, Mangum J, Sun W, Holder A, Ceder G, Gorman B, Teeter G, Tumas W, Zakutayev A. Redox-Mediated Stabilization in Zinc Molybdenum Nitrides. J Am Chem Soc 2018; 140:4293-4301. [PMID: 29494134 DOI: 10.1021/jacs.7b12861] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
We report on the theoretical prediction and experimental realization of new ternary zinc molybdenum nitride compounds. We used theory to identify previously unknown ternary compounds in the Zn-Mo-N systems, Zn3MoN4 and ZnMoN2, and to analyze their bonding environment. Experiments show that Zn-Mo-N alloys can form in broad composition range from Zn3MoN4 to ZnMoN2 in the wurtzite-derived structure, accommodating very large off-stoichiometry. Interestingly, the measured wurtzite-derived structure of the alloys is metastable for the ZnMoN2 stoichiometry, in contrast to the Zn3MoN4 stoichiometry, where ordered wurtzite is predicted to be the ground state. The formation of Zn3MoN4-ZnMoN2 alloy with wurtzite-derived crystal structure is enabled by the concomitant ability of Mo to change oxidation state from +VI in Zn3MoN4 to +IV in ZnMoN2, and the capability of Zn to contribute to the bonding states of both compounds, an effect that we define as "redox-mediated stabilization". The stabilization of Mo in both the +VI and +IV oxidation states is due to the intermediate electronegativity of Zn, which enables significant polar covalent bonding in both Zn3MoN4 and ZnMoN2 compounds. The smooth change in the Mo oxidation state between Zn3MoN4 and ZnMoN2 stoichiometries leads to a continuous change in optoelectronic properties-from resistive and semitransparent Zn3MoN4 to conductive and absorptive ZnMoN2. The reported redox-mediated stabilization in zinc molybdenum nitrides suggests there might be many undiscovered ternary compounds with one metal having an intermediate electronegativity, enabling significant covalent bonding, and another metal capable of accommodating multiple oxidation states, enabling stoichiometric flexibility.
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Affiliation(s)
- Elisabetta Arca
- National Renewable Energy Laboratory , Golden , Colorado 80401 , United States
| | - Stephan Lany
- National Renewable Energy Laboratory , Golden , Colorado 80401 , United States
| | - John D Perkins
- National Renewable Energy Laboratory , Golden , Colorado 80401 , United States
| | - Christopher Bartel
- Department of Chemical and Biological Engineering , University of Colorado Boulder , Boulder , Colorado 80309 , United States
| | - John Mangum
- Department of Metallurgical and Materials Engineering , Colorado School of Mines , Golden , Colorado 80401 , United States
| | - Wenhao Sun
- Materials Science Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Aaron Holder
- National Renewable Energy Laboratory , Golden , Colorado 80401 , United States.,Department of Chemical and Biological Engineering , University of Colorado Boulder , Boulder , Colorado 80309 , United States
| | - Gerbrand Ceder
- Materials Science Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States.,Department of Materials Science and Engineering , University of California Berkeley , Berkeley , California 94720 , United States
| | - Brian Gorman
- Department of Metallurgical and Materials Engineering , Colorado School of Mines , Golden , Colorado 80401 , United States
| | - Glenn Teeter
- National Renewable Energy Laboratory , Golden , Colorado 80401 , United States
| | - William Tumas
- National Renewable Energy Laboratory , Golden , Colorado 80401 , United States
| | - Andriy Zakutayev
- National Renewable Energy Laboratory , Golden , Colorado 80401 , United States
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