1
|
Varley JB, Ray KG, Lordi V. Dangling Bonds as Possible Contributors to Charge Noise in Silicon and Silicon-Germanium Quantum Dot Qubits. ACS Appl Mater Interfaces 2023; 15:43111-43123. [PMID: 37651689 DOI: 10.1021/acsami.3c06725] [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: 09/02/2023]
Abstract
Spin qubits based on Si and Si1-xGex quantum dot architectures exhibit among the best coherence times of competing quantum computing technologies, yet they still suffer from charge noise that limit their qubit gate fidelities. Identifying the origins of these charge fluctuations is therefore a critical step toward improving Si quantum-dot-based qubits. Here, we use hybrid functional calculations to investigate possible atomistic sources of charge noise, focusing on charge trapping at Si and Ge dangling bonds (DBs). We evaluate the role of global and local environment in the defect levels associated with DBs in Si, Ge, and Si1-xGex alloys, and consider their trapping and excitation energies within the framework of configuration coordinate diagrams. We additionally consider the influence of strain and oxidation in charge-trapping energetics by analyzing Si and GeSi DBs in SiO2 and strained Si layers in typical Si1-xGex quantum dot heterostructures. Our results identify that Ge dangling bonds are more problematic charge-trapping centers both in typical Si1-xGex alloys and associated oxidation layers, and they may be exacerbated by compositional inhomogeneities. These results suggest the importance of alloy homogeneity and possible passivation schemes for DBs in Si-based quantum dot qubits and are of general relevance to mitigating possible trap levels in other Si, Ge, and Si1-xGex-based metal-oxide-semiconductor stacks and related devices.
Collapse
Affiliation(s)
- Joel B Varley
- Materials Science Division, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - Keith G Ray
- Materials Science Division, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - Vincenzo Lordi
- Materials Science Division, Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| |
Collapse
|
2
|
Shivanna M, Zheng JJ, Ray KG, Lto S, Ashitani H, Kubota Y, Kawaguchi S, Stavila V, Yao MS, Fujikawa T, Otake KI, Kitagawa S. Selective sorption of oxygen and nitrous oxide by an electron donor-incorporated flexible coordination network. Commun Chem 2023; 6:62. [PMID: 37016050 PMCID: PMC10073098 DOI: 10.1038/s42004-023-00853-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2022] [Accepted: 03/10/2023] [Indexed: 04/06/2023] Open
Abstract
Incorporating strong electron donor functionality into flexible coordination networks is intriguing for sorption applications due to a built-in mechanism for electron-withdrawing guests. Here we report a 2D flexible porous coordination network, [Ni2(4,4'-bipyridine)(VTTF)2]n(1) (where H2VTTF = 2,2'-[1,2-bis(4-benzoic acid)-1,2ethanediylidene]bis-1,3-benzodithiole), which exhibits large structural deformation from the as-synthesized or open phase (1α) into the closed phase (1β) after guest removal, as demonstrated by X-ray and electron diffraction. Interestingly, upon exposure to electron-withdrawing species, 1β reversibly undergoes guest accommodation transitions; 1α⊃O2 (90 K) and 1α⊃N2O (185 K). Moreover, the 1β phase showed exclusive O2 sorption over other gases (N2, Ar, and CO) at 120 K. The phase transformations between the 1α and 1β phases under these gases were carefully investigated by in-situ X-ray diffraction, in-situ spectroscopic studies, and DFT calculations, validating that the unusual sorption was attributed to the combination of flexible frameworks and VTTF (electron-donor) that induces strong interactions with electron-withdrawing species.
Collapse
Affiliation(s)
- Mohana Shivanna
- Institute for Integrated Cell-Material Sciences, Kyoto University Institute for Advanced Study, Kyoto University, Yoshida Ushinomiya-cho, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Jia-Jia Zheng
- Institute for Integrated Cell-Material Sciences, Kyoto University Institute for Advanced Study, Kyoto University, Yoshida Ushinomiya-cho, Sakyo-ku, Kyoto, 606-8501, Japan
- Laboratory of Theoretical and Computational Nanoscience, CAS Center for Excellence in Nanoscience, National Center for Nanoscience and Technology, Chinese Academy of Sciences, No. 11 ZhongGuanCun BeiYiTiao, Beijing, 100190, P. R. China
| | - Keith G Ray
- Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Sho Lto
- Rigaku Corporation, 3-9-12 Matsubara-cho, Akishima, Tokyo, 196-8666, Japan
| | - Hirotaka Ashitani
- Department of Physics, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka, 599-8531, Japan
| | - Yoshiki Kubota
- Department of Physics, Graduate School of Science, Osaka Prefecture University, Sakai, Osaka, 599-8531, Japan
- Department of Physical Science, Graduate School of Science, Osaka Metropolitan University, Sakai, Osaka, 599-8531, Japan
| | - Shogo Kawaguchi
- Japan Synchrotron Radiation Research Institute (JASRI), SPring-8, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5198, Japan
| | | | - Ming-Shui Yao
- Institute for Integrated Cell-Material Sciences, Kyoto University Institute for Advanced Study, Kyoto University, Yoshida Ushinomiya-cho, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Takao Fujikawa
- Institute for Integrated Cell-Material Sciences, Kyoto University Institute for Advanced Study, Kyoto University, Yoshida Ushinomiya-cho, Sakyo-ku, Kyoto, 606-8501, Japan
| | - Ken-Ichi Otake
- Institute for Integrated Cell-Material Sciences, Kyoto University Institute for Advanced Study, Kyoto University, Yoshida Ushinomiya-cho, Sakyo-ku, Kyoto, 606-8501, Japan.
| | - Susumu Kitagawa
- Institute for Integrated Cell-Material Sciences, Kyoto University Institute for Advanced Study, Kyoto University, Yoshida Ushinomiya-cho, Sakyo-ku, Kyoto, 606-8501, Japan.
| |
Collapse
|
3
|
Gunda H, Ray KG, Klebanoff LE, Dun C, Marple MAT, Li S, Sharma P, Friddle RW, Sugar JD, Snider JL, Horton RD, Davis BC, Chames JM, Liu YS, Guo J, Mason HE, Urban JJ, Wood BC, Allendorf MD, Jasuja K, Stavila V. Hydrogen Storage in Partially Exfoliated Magnesium Diboride Multilayers. Small 2023; 19:e2205487. [PMID: 36470595 DOI: 10.1002/smll.202205487] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 10/26/2022] [Indexed: 06/17/2023]
Abstract
Metal boride nanostructures have shown significant promise for hydrogen storage applications. However, the synthesis of nanoscale metal boride particles is challenging because of their high surface energy, strong inter- and intraplanar bonding, and difficult-to-control surface termination. Here, it is demonstrated that mechanochemical exfoliation of magnesium diboride in zirconia produces 3-4 nm ultrathin MgB2 nanosheets (multilayers) in high yield. High-pressure hydrogenation of these multilayers at 70 MPa and 330 °C followed by dehydrogenation at 390 °C reveals a hydrogen capacity of 5.1 wt%, which is ≈50 times larger than the capacity of bulk MgB2 under the same conditions. This enhancement is attributed to the creation of defective sites by ball-milling and incomplete Mg surface coverage in MgB2 multilayers, which disrupts the stable boron-boron ring structure. The density functional theory calculations indicate that the balance of Mg on the MgB2 nanosheet surface changes as the material hydrogenates, as it is energetically favorable to trade a small number of Mg vacancies in Mg(BH4 )2 for greater Mg coverage on the MgB2 surface. The exfoliation and creation of ultrathin layers is a promising new direction for 2D metal boride/borohydride research with the potential to achieve high-capacity reversible hydrogen storage at more moderate pressures and temperatures.
Collapse
Affiliation(s)
- Harini Gunda
- Sandia National Laboratories, 7011 East Ave, Livermore, CA, 94550, USA
- Indian Institute of Technology Gandhinagar, Palaj, Gandhinagar, Gujarat, 382355, India
| | - Keith G Ray
- Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, CA, 94550, USA
| | | | - Chaochao Dun
- Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Maxwell A T Marple
- Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, CA, 94550, USA
| | - Sichi Li
- Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, CA, 94550, USA
| | - Peter Sharma
- Sandia National Laboratories, 1515 Eubank SE, Albuquerque, NM, 87185, USA
| | - Raymond W Friddle
- Sandia National Laboratories, 7011 East Ave, Livermore, CA, 94550, USA
| | - Joshua D Sugar
- Sandia National Laboratories, 7011 East Ave, Livermore, CA, 94550, USA
| | - Jonathan L Snider
- Sandia National Laboratories, 7011 East Ave, Livermore, CA, 94550, USA
| | - Robert D Horton
- Sandia National Laboratories, 7011 East Ave, Livermore, CA, 94550, USA
| | - Brendan C Davis
- Sandia National Laboratories, 7011 East Ave, Livermore, CA, 94550, USA
| | - Jeffery M Chames
- Sandia National Laboratories, 7011 East Ave, Livermore, CA, 94550, USA
| | - Yi-Sheng Liu
- Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Jinghua Guo
- Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Harris E Mason
- Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, CA, 94550, USA
| | - Jeffrey J Urban
- Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Brandon C Wood
- Lawrence Livermore National Laboratory, 7000 East Ave, Livermore, CA, 94550, USA
| | - Mark D Allendorf
- Sandia National Laboratories, 7011 East Ave, Livermore, CA, 94550, USA
| | - Kabeer Jasuja
- Indian Institute of Technology Gandhinagar, Palaj, Gandhinagar, Gujarat, 382355, India
| | - Vitalie Stavila
- Sandia National Laboratories, 7011 East Ave, Livermore, CA, 94550, USA
| |
Collapse
|
4
|
Ray KG, Klebanoff LE, Stavila V, Kang S, Wan LF, Li S, Heo TW, Allendorf MD, Lee JRI, Baker AA, Wood BC. Understanding Hydrogenation Chemistry at MgB 2 Reactive Edges from Ab Initio Molecular Dynamics. ACS Appl Mater Interfaces 2022; 14:20430-20442. [PMID: 35319201 DOI: 10.1021/acsami.1c23524] [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: 06/14/2023]
Abstract
Solid-state hydrogen storage materials often operate via transient, multistep chemical reactions at complex interfaces that are difficult to capture. Here, we use direct ab initio molecular dynamics simulations at accelerated temperatures and hydrogen pressures to probe the hydrogenation chemistry of the candidate material MgB2 without a priori assumption of reaction pathways. Focusing on highly reactive (101̅0) edge planes where initial hydrogen attack is likely to occur, we track mechanistic steps toward the formation of hydrogen-saturated BH4- units and key chemical intermediates, involving H2 dissociation, generation of functionalities and molecular complexes containing BH2 and BH3 motifs, and B-B bond breaking. The genesis of higher-order boron clustering is also observed. Different charge states and chemical environments at the B-rich and Mg-rich edge planes are found to produce different chemical pathways and preferred speciation, with implications for overall hydrogenation kinetics. The reaction processes rely on B-H bond polarization and fluctuations between ionic and covalent character, which are critically enabled by the presence of Mg2+ cations in the nearby interphase region. Our results provide guidance for devising kinetic improvement strategies for MgB2-based hydrogen storage materials, while also providing a template for exploring chemical pathways in other solid-state energy storage reactions.
Collapse
Affiliation(s)
- Keith G Ray
- Laboratory for Energy Applications for the Future (LEAF), Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | | | - Vitalie Stavila
- Sandia National Laboratories, Livermore, California 94551, United States
| | - ShinYoung Kang
- Laboratory for Energy Applications for the Future (LEAF), Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - Liwen F Wan
- Laboratory for Energy Applications for the Future (LEAF), Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - Sichi Li
- Laboratory for Energy Applications for the Future (LEAF), Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - Tae Wook Heo
- Laboratory for Energy Applications for the Future (LEAF), Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - Mark D Allendorf
- Sandia National Laboratories, Livermore, California 94551, United States
| | - Jonathan R I Lee
- Laboratory for Energy Applications for the Future (LEAF), Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - Alexander A Baker
- Laboratory for Energy Applications for the Future (LEAF), Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| | - Brandon C Wood
- Laboratory for Energy Applications for the Future (LEAF), Lawrence Livermore National Laboratory, Livermore, California 94550, United States
| |
Collapse
|
5
|
Li S, Gunda H, Ray KG, Wong CS, Xiao P, Friddle RW, Liu YS, Kang S, Dun C, Sugar JD, Kolasinski RD, Wan LF, Baker AA, Lee JRI, Urban JJ, Jasuja K, Allendorf MD, Stavila V, Wood BC. Spontaneous dynamical disordering of borophenes in MgB 2 and related metal borides. Nat Commun 2021; 12:6268. [PMID: 34725350 PMCID: PMC8560812 DOI: 10.1038/s41467-021-26512-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Accepted: 09/29/2021] [Indexed: 11/30/2022] Open
Abstract
Layered boron compounds have attracted significant interest in applications from energy storage to electronic materials to device applications, owing in part to a diversity of surface properties tied to specific arrangements of boron atoms. Here we report the energy landscape for surface atomic configurations of MgB2 by combining first-principles calculations, global optimization, material synthesis and characterization. We demonstrate that contrary to previous assumptions, multiple disordered reconstructions are thermodynamically preferred and kinetically accessible within exposed B surfaces in MgB2 and other layered metal diborides at low boron chemical potentials. Such a dynamic environment and intrinsic disordering of the B surface atoms present new opportunities to realize a diverse set of 2D boron structures. We validated the predicted surface disorder by characterizing exfoliated boron-terminated MgB2 nanosheets. We further discuss application-relevant implications, with a particular view towards understanding the impact of boron surface heterogeneity on hydrogen storage performance. Layered boron compounds attract enormous interest in applications. This work reports first-principles calculations coupled with global optimization to show that the outer boron surface in MgB2 nanosheets undergo disordering and clustering, which is experimentally confirmed in synthesized MgB2 nanosheets.
Collapse
Affiliation(s)
- Sichi Li
- Materials Science Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA.
| | - Harini Gunda
- Sandia National Laboratories, Livermore, CA, 94551, USA.,Department of Chemical Engineering, Indian Institute of Technology, Gandhinagar, Gujarat, 382355, India
| | - Keith G Ray
- Materials Science Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | | | - Penghao Xiao
- Materials Science Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | | | - Yi-Sheng Liu
- Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - ShinYoung Kang
- Materials Science Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Chaochao Dun
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | | | | | - Liwen F Wan
- Materials Science Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Alexander A Baker
- Materials Science Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Jonathan R I Lee
- Materials Science Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA
| | - Jeffrey J Urban
- Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Kabeer Jasuja
- Department of Chemical Engineering, Indian Institute of Technology, Gandhinagar, Gujarat, 382355, India
| | | | | | - Brandon C Wood
- Materials Science Division, Lawrence Livermore National Laboratory, Livermore, CA, 94550, USA.
| |
Collapse
|
6
|
Jeong S, Heo TW, Oktawiec J, Shi R, Kang S, White JL, Schneemann A, Zaia EW, Wan LF, Ray KG, Liu YS, Stavila V, Guo J, Long JR, Wood BC, Urban JJ. A Mechanistic Analysis of Phase Evolution and Hydrogen Storage Behavior in Nanocrystalline Mg(BH 4) 2 within Reduced Graphene Oxide. ACS Nano 2020; 14:1745-1756. [PMID: 31922396 DOI: 10.1021/acsnano.9b07454] [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] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Magnesium borohydride (Mg(BH4)2, abbreviated here MBH) has received tremendous attention as a promising onboard hydrogen storage medium due to its excellent gravimetric and volumetric hydrogen storage capacities. While the polymorphs of MBH-alpha (α), beta (β), and gamma (γ)-have distinct properties, their synthetic homogeneity can be difficult to control, mainly due to their structural complexity and similar thermodynamic properties. Here, we describe an effective approach for obtaining pure polymorphic phases of MBH nanomaterials within a reduced graphene oxide support (abbreviated MBHg) under mild conditions (60-190 °C under mild vacuum, 2 Torr), starting from two distinct samples initially dried under Ar and vacuum. Specifically, we selectively synthesize the thermodynamically stable α phase and metastable β phase from the γ-phase within the temperature range of 150-180 °C. The relevant underlying phase evolution mechanism is elucidated by theoretical thermodynamics and kinetic nucleation modeling. The resulting MBHg composites exhibit structural stability, resistance to oxidation, and partially reversible formation of diverse [BH4]- species during de- and rehydrogenation processes, rendering them intriguing candidates for further optimization toward hydrogen storage applications.
Collapse
Affiliation(s)
- Sohee Jeong
- The Molecular Foundry, Materials Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Tae Wook Heo
- Materials Science Division , Lawrence Livermore National Laboratory , Livermore , California 94550 , United States
| | - Julia Oktawiec
- Department of Chemistry , University of California , Berkeley , California 94720 , United States
- Materials Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Rongpei Shi
- Materials Science Division , Lawrence Livermore National Laboratory , Livermore , California 94550 , United States
| | - ShinYoung Kang
- Materials Science Division , Lawrence Livermore National Laboratory , Livermore , California 94550 , United States
| | - James L White
- Chemistry, Combustion, and Materials Science Center , Sandia National Laboratories , Livermore , California 94550 , United States
| | - Andreas Schneemann
- Chemistry, Combustion, and Materials Science Center , Sandia National Laboratories , Livermore , California 94550 , United States
| | - Edmond W Zaia
- The Molecular Foundry, Materials Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Liwen F Wan
- Materials Science Division , Lawrence Livermore National Laboratory , Livermore , California 94550 , United States
| | - Keith G Ray
- Materials Science Division , Lawrence Livermore National Laboratory , Livermore , California 94550 , United States
| | - Yi-Sheng Liu
- Advanced Light Source , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| | - Vitalie Stavila
- Chemistry, Combustion, and Materials Science Center , Sandia National Laboratories , Livermore , California 94550 , United States
| | - Jinghua Guo
- Advanced Light Source , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
- Department of Chemistry and Biochemistry , University of California , Santa Cruz , California 95064 , United States
| | - Jeffrey R Long
- Department of Chemistry , University of California , Berkeley , California 94720 , United States
- Materials Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
- Department of Chemical and Biomolecular Engineering , University of California , Berkeley , California 94720 , United States
| | - Brandon C Wood
- Materials Science Division , Lawrence Livermore National Laboratory , Livermore , California 94550 , United States
| | - Jeffrey J Urban
- The Molecular Foundry, Materials Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States
| |
Collapse
|
7
|
Ray KG, Klebanoff LE, Lee JRI, Stavila V, Heo TW, Shea P, Baker AA, Kang S, Bagge-Hansen M, Liu YS, White JL, Wood BC. Elucidating the mechanism of MgB2 initial hydrogenation via a combined experimental–theoretical study. Phys Chem Chem Phys 2017; 19:22646-22658. [DOI: 10.1039/c7cp03709k] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The initial hydrogenation of MgB2 occurs via a multi-step process, which can result in the direct production of [BH4]− complexes.
Collapse
Affiliation(s)
- Keith G. Ray
- Lawrence Livermore National Laboratory
- Livermore
- USA
| | | | | | | | - Tae Wook Heo
- Lawrence Livermore National Laboratory
- Livermore
- USA
| | - Patrick Shea
- Lawrence Livermore National Laboratory
- Livermore
- USA
| | | | | | | | - Yi-Sheng Liu
- Lawrence Berkeley National Laboratory
- Berkeley
- USA
| | | | | |
Collapse
|
8
|
Begtrup GE, Ray KG, Kessler BM, Yuzvinsky TD, Garcia H, Zettl A. Probing nanoscale solids at thermal extremes. Phys Rev Lett 2007; 99:155901. [PMID: 17995185 DOI: 10.1103/physrevlett.99.155901] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2007] [Revised: 06/13/2007] [Indexed: 05/06/2023]
Abstract
We report a novel nanoscale thermal platform compatible with extreme temperature operation and real-time high-resolution transmission electron microscopy. Applied to multiwall carbon nanotubes, we find atomic-scale stability to 3200 K, demonstrating that carbon nanotubes are more robust than graphite or diamond. Even at these thermal extremes, nanotubes maintain 10% of their peak thermal conductivity and support electrical current densities approximately 2 x 10{8} A/cm{2}. We also apply this platform to determine the diameter dependence of the melting temperature of gold nanocrystals down to three nanometers.
Collapse
Affiliation(s)
- G E Begtrup
- Department of Physics, University of California at Berkeley, Berkeley, California 94720, USA
| | | | | | | | | | | |
Collapse
|