1
|
Sun Y, Qian G, Pang S, Lu J, Guo J, Wang Z. Partition model for trace elements between liquid metal and silicate melts involving the interfacial transition structure: An exploratory two-phase first-principles molecular dynamics study. J Mol Liq 2022. [DOI: 10.1016/j.molliq.2022.120048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
|
2
|
Li W, Zhao X, Liu C, Coudert FX. Ab Initio Molecular Dynamics of CdSe Quantum-Dot-Doped Glasses. J Am Chem Soc 2020; 142:3905-3912. [PMID: 32011133 DOI: 10.1021/jacs.9b12073] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
We have probed the local atomic structure of the interface between a CdSe quantum dot (QD) and a sodium silicate glass matrix. Using ab initio molecular dynamics simulations, we determined the structural properties and bond lengths, in excellent agreement with previous experimental observations. On the basis of an analysis of radial distribution functions, coordination environment, and ring structures, we demonstrate that an important structural reconstruction occurs at the interface between the CdSe QD and the glass matrix. The incorporation of the CdSe QD disrupts the Na-O bonds, while stronger SiO4 tetrahedra are reformed. The existence of the glass matrix breaks the stable 4-membered (4MR) and 6-membered (6MR) Cd-Se rings, and we observe a disassociated Cd atom migrated in the glass matrix. Besides, the formation of Se-Na and Cd-O linkages is observed at the CdSe QD/glass interface. These results significantly extend our understanding of the interfacial structure of CdSe QD-doped glasses and provide physical and chemical insight into the possible defect structure origin of CdSe QD, of interest to the fabrication of the highly luminescent CdSe QD-doped glasses.
Collapse
Affiliation(s)
- Wenke Li
- State Key Laboratory of Silicate Materials for Architectures , Wuhan University of Technology , Hubei 430070 , China.,Chimie ParisTech, PSL University, CNRS, Institut de Recherche de Chimie Paris , 75005 Paris , France
| | - Xiujian Zhao
- State Key Laboratory of Silicate Materials for Architectures , Wuhan University of Technology , Hubei 430070 , China
| | - Chao Liu
- State Key Laboratory of Silicate Materials for Architectures , Wuhan University of Technology , Hubei 430070 , China
| | - François-Xavier Coudert
- Chimie ParisTech, PSL University, CNRS, Institut de Recherche de Chimie Paris , 75005 Paris , France
| |
Collapse
|
3
|
Konstantinou K, Mocanu FC, Lee TH, Elliott SR. Ab initio computer simulations of non-equilibrium radiation-induced cascades in amorphous Ge 2Sb 2Te 5. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2018; 30:455401. [PMID: 30239335 DOI: 10.1088/1361-648x/aae340] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Ion irradiation corresponds to a process that involves the production of non-equilibrium cascades in the host material, and the atomistic modelling of such events in glasses is challenging. Here, non-equilibrium cascades in amorphous Ge2Sb2Te5 phase-change memory material have been investigated by means of first-principles molecular-dynamics simulations. A stochastic boundary-conditions approach is employed to treat the thermal nature of the cascades and drive the modelled system back to equilibrium in a natural way, while four different initial thermal-spike energies are considered. A comprehensive analysis of the cascade evolution is presented with respect to the kinetic profile and the dynamics of the cascade inside the glass structure. The modelling results show that the instantaneous maximum kinetic energy decays rapidly with time, and that the time-scale of the ballistic phase of the cascade inside the glass model is very short. The quality of the implemented approach is validated through a comparison of the calculated structure factor for the modelled glasses with experimental data from the literature. Analysis of the bonding for all the species in the glass structure highlights particular structural modifications in the connectivity of the amorphous network due to the simulated cascade.
Collapse
Affiliation(s)
- K Konstantinou
- Department of Chemistry, University of Cambridge, CB2 1EW Cambridge, United Kingdom
| | | | | | | |
Collapse
|
4
|
Nakase M, Matsuzawa Y, Takeshita K. Continuous separation of molybdenum and zirconium from simulated high-level liquid waste with a Taylor–Couette contactor. J NUCL SCI TECHNOL 2018. [DOI: 10.1080/00223131.2018.1509029] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Affiliation(s)
- Masahiko Nakase
- Laboratory for Advanced Nuclear Energy, Tokyo Institute of Technology, Tokyo, Japan
| | - Yuto Matsuzawa
- Laboratory for Advanced Nuclear Energy, Tokyo Institute of Technology, Tokyo, Japan
| | - Kenji Takeshita
- Laboratory for Advanced Nuclear Energy, Tokyo Institute of Technology, Tokyo, Japan
| |
Collapse
|
5
|
Brehault A, Patil D, Kamat H, Youngman RE, Thirion LM, Mauro JC, Corkhill CL, McCloy JS, Goel A. Compositional Dependence of Solubility/Retention of Molybdenum Oxides in Aluminoborosilicate-Based Model Nuclear Waste Glasses. J Phys Chem B 2018; 122:1714-1729. [PMID: 29332394 DOI: 10.1021/acs.jpcb.7b09158] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Molybdenum oxides are an integral component of the high-level waste streams being generated from the nuclear reactors in several countries. Although borosilicate glass has been chosen as the baseline waste form by most of the countries to immobilize these waste streams, molybdate oxyanions (MoO42-) exhibit very low solubility (∼1 mol %) in these glass matrices. In the past three to four decades, several studies describing the compositional and structural dependence of molybdate anions in borosilicate and aluminoborosilicate glasses have been reported in the literature, providing a basis for our understanding of fundamental science that governs the solubility and retention of these species in the nuclear waste glasses. However, there are still several open questions that need to be answered to gain an in-depth understanding of the mechanisms that control the solubility and retention of these oxyanions in glassy waste forms. This article is focused on finding answers to two such questions: (1) What are the solubility and retention limits of MoO3 in aluminoborosilicate glasses as a function of chemical composition? (2) Why is there a considerable increase in the solubility of MoO3 with incorporation of rare-earth oxides (for example, Nd2O3) in aluminoborosilicate glasses? Accordingly, three different series of aluminoborosilicate glasses (compositional complexity being added in a tiered approach) with varying MoO3 concentrations have been synthesized and characterized for their ability to accommodate molybdate ions in their structure (solubility) and as a glass-ceramic (retention). The contradictory viewpoints (between different research groups) pertaining to the impact of rare-earth cations on the structure of aluminoborosilicate glasses are discussed, and their implications on the solubility of MoO3 in these glasses are evaluated. A novel hypothesis explaining the mechanism governing the solubility of MoO3 in rare-earth containing aluminoborosilicate glasses has been proposed.
Collapse
Affiliation(s)
- Antoine Brehault
- Department of Materials Science and Engineering, Rutgers - The State University of New Jersey , Piscataway, New Jersey 08854, United States
| | - Deepak Patil
- School of Mechanical & Materials Engineering and Materials Science & Engineering Program, Washington State University , Pullman, Washington 99164, United States
| | - Hrishikesh Kamat
- Department of Materials Science and Engineering, Rutgers - The State University of New Jersey , Piscataway, New Jersey 08854, United States
| | - Randall E Youngman
- Corning Research & Development Corporation , Corning, New York 14831, United States
| | - Lynn M Thirion
- Corning Research & Development Corporation , Corning, New York 14831, United States
| | - John C Mauro
- Department of Materials Science and Engineering, The Pennsylvania State University , University Park, Pennsylvania 16802, United States
| | - Claire L Corkhill
- NucleUS Immobilisation Science Laboratory, Department of Materials Science and Engineering, The University of Sheffield , Sheffield S10 2TN, U.K
| | - John S McCloy
- School of Mechanical & Materials Engineering and Materials Science & Engineering Program, Washington State University , Pullman, Washington 99164, United States.,NucleUS Immobilisation Science Laboratory, Department of Materials Science and Engineering, The University of Sheffield , Sheffield S10 2TN, U.K
| | - Ashutosh Goel
- Department of Materials Science and Engineering, Rutgers - The State University of New Jersey , Piscataway, New Jersey 08854, United States
| |
Collapse
|