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Abstract
A quantitative thermodynamic model for the size-dependent formation enthalpy of nanocompounds is proposed. The model reveals that the thermal stability of nanocompounds decreases because of the size dependence of formation enthalpy when the size of these nanostructures decreases. This stability loss is related to some general phenomena such as interface alloying of immiscible systems and phase segregation of miscible systems with reducing system sizes. The predictions from the model are in agreement with the results from density function theory calculation for MgH2, the experimental measurement of SnTe nanoparticles, and quantum chemistry consideration.
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Affiliation(s)
- L H Liang
- Department of Physics, National University of Singapore, Singapore 117542, Republic of Singapore
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José-Yacaman M, Gutierrez-Wing C, Miki M, Yang DQ, Piyakis KN, Sacher E. Surface Diffusion and Coalescence of Mobile Metal Nanoparticles. J Phys Chem B 2005; 109:9703-11. [PMID: 16852169 DOI: 10.1021/jp0509459] [Citation(s) in RCA: 166] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The diffusion and coalescence of metal nanoparticles play important roles in many phenomena. Here, we offer a new integrated overview of the main factors that control the nanoparticle coalescence process. Three factors are considered in our description of the coalescence process: nanoparticle diffusion across the surface, their physical and thermodynamic properties, and the mechanism of coalescence. We demonstrate that the liquid-like properties of the surface layers of the nanoparticles play an essential role in this process. We present experimental evidence for our opinion, based on the high-resolution electron microscopic analysis of several different types of nanoparticles.
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Affiliation(s)
- M José-Yacaman
- Center for Nano and Molecular Technology, Texas Materials Institute, Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712, USA
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53
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Sun CQ, Li S, Li CM. Impact of Bond Order Loss on Surface and Nanosolid Mechanics. J Phys Chem B 2004; 109:415-23. [PMID: 16851031 DOI: 10.1021/jp045894e] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
An analytical solution shows that a competition between bond order loss and the associated bond strength gain of the lower coordinated atoms near the edge of a surface dictates the mechanics of the surface and, hence, a nanosolid. Bond order loss lowers the activation energy for atomic dislocation, whereas bond strength gain enhances the energy density or mechanical strength in the region near the surface. Therefore, the surface is harder than the bulk interior at temperatures far below the melting point (T(m)), and the surface becomes softer at temperatures close to the surface T(m) that drops because of bond order loss. Matching predictions to measurements reveals that a transition happens to the Hall-Petch relationship for a nanosolid when the effect of bond order loss becomes dominant, and the critical size of the Hall-Petch transition depends intrinsically on the bond nature of the specimen and the ratio of T/T(m), where T is the temperature of operation.
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Affiliation(s)
- Chang Q Sun
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, Singapore.
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Harinipriya S, Sangaranarayanan MV. Stability of Scanning Tunneling Microscopy Tip-Induced Bimetallic Nanoclusters: Influence of Hardness and Composition on the Cohesive Energies. J Phys Chem B 2004. [DOI: 10.1021/jp0368942] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- S. Harinipriya
- Department of Chemistry, Indian Institute of Technology, Madras, 600 036, India
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55
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Pan LK, Sun CQ, Li CM. Elucidating Si−Si Dimmer Vibration from the Size-Dependent Raman Shift of Nanosolid Si. J Phys Chem B 2004. [DOI: 10.1021/jp037891s] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- L. K. Pan
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798
| | - Chang Q. Sun
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798
| | - C. M. Li
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798
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56
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Sun CQ, Bai HL, Li S, Tay BK, Li C, Chen TP, Jiang EY. Length, Strength, Extensibility, and Thermal Stability of a Au−Au Bond in the Gold Monatomic Chain. J Phys Chem B 2004. [DOI: 10.1021/jp035815j] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Chang Q. Sun
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, and Institute of Advanced Materials Physics and Faculty of Science, Tianjin University, Tianjin 30072, People's Republic of China
| | - H. L. Bai
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, and Institute of Advanced Materials Physics and Faculty of Science, Tianjin University, Tianjin 30072, People's Republic of China
| | - S. Li
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, and Institute of Advanced Materials Physics and Faculty of Science, Tianjin University, Tianjin 30072, People's Republic of China
| | - B. K. Tay
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, and Institute of Advanced Materials Physics and Faculty of Science, Tianjin University, Tianjin 30072, People's Republic of China
| | - C. Li
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, and Institute of Advanced Materials Physics and Faculty of Science, Tianjin University, Tianjin 30072, People's Republic of China
| | - T. P. Chen
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, and Institute of Advanced Materials Physics and Faculty of Science, Tianjin University, Tianjin 30072, People's Republic of China
| | - E. Y. Jiang
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, and Institute of Advanced Materials Physics and Faculty of Science, Tianjin University, Tianjin 30072, People's Republic of China
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57
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Band-gap expansion, core-level shift, and dielectric suppression of porous silicon passivated by plasma fluorination. ACTA ACUST UNITED AC 2004. [DOI: 10.1116/1.1651108] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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58
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Sun CQ, Zhong WH, Li S, Tay BK, Bai HL, Jiang EY. Coordination Imperfection Suppressed Phase Stability of Ferromagnetic, Ferroelectric, and Superconductive Nanosolids. J Phys Chem B 2003. [DOI: 10.1021/jp0372946] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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59
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Sun CQ, Bai HL, Tay BK, Li S, Jiang EY. Dimension, Strength, and Chemical and Thermal Stability of a Single C−C Bond in Carbon Nanotubes. J Phys Chem B 2003. [DOI: 10.1021/jp035070h] [Citation(s) in RCA: 106] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Chang Q. Sun
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, and Institute of Advanced Materials Physics and Faculty of Science, Tianjin University, 30072, People's Republic of China
| | - H. L. Bai
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, and Institute of Advanced Materials Physics and Faculty of Science, Tianjin University, 30072, People's Republic of China
| | - B. K. Tay
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, and Institute of Advanced Materials Physics and Faculty of Science, Tianjin University, 30072, People's Republic of China
| | - S. Li
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, and Institute of Advanced Materials Physics and Faculty of Science, Tianjin University, 30072, People's Republic of China
| | - E. Y. Jiang
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 639798, and Institute of Advanced Materials Physics and Faculty of Science, Tianjin University, 30072, People's Republic of China
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Sun CQ, Tay BK, Fu YQ, Li S, Chen TP, Bai HL, Jiang EY. Discriminating Crystal Binding from the Atomic Trapping of a Core Electron at Energy Levels Shifted by Surface Relaxation or Nanosolid Formation. J Phys Chem B 2002. [DOI: 10.1021/jp027027k] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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61
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Pan LK, Sun CQ, Tay BK, Chen TP, Li S. Photoluminescence of Si Nanosolids near the Lower End of the Size Limit. J Phys Chem B 2002. [DOI: 10.1021/jp0266805] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- L. K. Pan
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 6397987
| | - C. Q. Sun
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 6397987
| | - B. K. Tay
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 6397987
| | - T. P. Chen
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 6397987
| | - S. Li
- School of Electrical and Electronic Engineering, Nanyang Technological University, Singapore 6397987
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