Browsing by Author Nguyen, Thi Thanh Ha

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  • 4231-97-8271-1-10-20180320.pdf.jpg
  • Article


  • Authors: Nguyen, Thi Thanh Ha; Kankham, Keopanya; Le, Van Vinh (2018)

  • In this paper the structural and dynamical characteristics in alumina- silicate Al2O3–2SiO2 (AS2) liquid are investigated by molecular simulation method. Structural properties are clarified through the pair radial distribution function, distribution of TOn (T= Si, Al) coordination units and distribution of partial bond angle in TOn. Furthermore the change in diffusion mechanism between low and high pressure is revealed by transition of the structural units TOx → TOx±1. At the low-pressure configuration of the liquid AS2 exhibits the dynamics heterogeneity (DH). The original of dynamic heterogeneity is identified and liquid AS2 consists of separate mobile and immobile regions.

  • 4295-97-8478-1-10-20181217.pdf.jpg
  • Article


  • Authors: Nguyen, Thi Thanh Ha; Phan, Quan; Tran, Van Hong; Le, Van Vinh (2018)

  • We perform a molecular dynamics simulation to study the microstructure and dynamical properties in large silica model at liquid state. The models consisting of 19998 atoms were constructed under a wide range of pressure (0-20 GPa) and at 3500K temperature. Structural characteristics were clarified through the pair radial distribution function (PRDF), the distribution of SiOx coordination units and network structure. The result shows that these liquids consist of identical units SiO4, SiO5 and SiO6 and have common partial O―Si―O angle distribution. Furthermore, the major change in the diffusion mechanism under pressure is also considered and discussed

  • 85.pdf.jpg
  • Article


  • Authors: Nguyen, Thi Thanh Ha; Pham, Khac Hung (2013)

  • Diffusion mechanism and dynamics in Al2O3 liquidhave been studied via molecular dynamics simulation. Six models with different density and at temperature of 3000 K have been used to study the atomistic mechanism governing the process of the bond-breaking and bond-reformation (the transition AlOx®AlOx+1 and AlOx®AlOx-1). Calculation shows that the diffusion of particle Al is realized via the transition AlOx®AlOx±1 and the rate of transition AlOx®AlOx±1 monotonously increases with pressure. When applying pressure to liquid the diffusion mechanism changes from strong localization of transitions SiOx®SiOx±1 in the sample at ambient pressure to uniform distribution transitions SiOx®SiOx±1...

  • TL1.pdf.jpg
  • Article


  • Authors: Nguyen, Thi Thanh Ha; Nguyen, Anh Dung; Nguyen, Quang Bau; Pham, Khac Hung (2016)

  • We have studied the diffusion mechanism in network-forming liquids via molecular dynamics simulation. Two models of silica liquid at temperatures of 2600 and 3500 K have been constructed. The motion of atoms is analyzed through reactions SiOx®SiOx±1, OSiy®OSiy±1 and coordination cells. It was shown that the reactions happen not randomly in the space, but they occur more frequently with some coordination cells and bonds Si-O. This effect enhances upon lowering the temperature. The number of reactions happening in the coordination cells is strongly correlated with the mobility of CC atom. We found that there are large rigid clusters which compose of immobile atoms and exist for long tim...

  • The Microstructural Transformation and Dynamical Properties in Sodium-silicate Molecular Dynamics Simulation.pdf.jpg
  • Article


  • Authors: Nguyen, Thi Thanh Ha; Tran, Thuy Duong; Nguyen, Hoai Anh (2020)

  • Molecular dynamics simulation of sodium-silicate has been carried out to investigate the microstructural transformation and diffusion mechanism. The microstructure of sodium silicate is studied by the pair radial distribution function, distribution of SiOx (x=4,5,6), OSiy (y=2,3) basic unit, bond angle distribution. The simulation results show that the structure of sodium silicate occurs the transformation from a tetrahedral structure to an octahedral structure under pressure. The additional network-modifying cation oxide breaking up this network by the generation of non-bridging O atoms and it has a slight effect on the topology of SiOx and OSiy units. Moreover, the diffusion of netw...

Browsing by Author Nguyen, Thi Thanh Ha

Jump to: 0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
or enter first few letters:  
Showing results 4 to 9 of 9
  • 4231-97-8271-1-10-20180320.pdf.jpg
  • Article


  • Authors: Nguyen, Thi Thanh Ha; Kankham, Keopanya; Le, Van Vinh (2018)

  • In this paper the structural and dynamical characteristics in alumina- silicate Al2O3–2SiO2 (AS2) liquid are investigated by molecular simulation method. Structural properties are clarified through the pair radial distribution function, distribution of TOn (T= Si, Al) coordination units and distribution of partial bond angle in TOn. Furthermore the change in diffusion mechanism between low and high pressure is revealed by transition of the structural units TOx → TOx±1. At the low-pressure configuration of the liquid AS2 exhibits the dynamics heterogeneity (DH). The original of dynamic heterogeneity is identified and liquid AS2 consists of separate mobile and immobile regions.

  • 4295-97-8478-1-10-20181217.pdf.jpg
  • Article


  • Authors: Nguyen, Thi Thanh Ha; Phan, Quan; Tran, Van Hong; Le, Van Vinh (2018)

  • We perform a molecular dynamics simulation to study the microstructure and dynamical properties in large silica model at liquid state. The models consisting of 19998 atoms were constructed under a wide range of pressure (0-20 GPa) and at 3500K temperature. Structural characteristics were clarified through the pair radial distribution function (PRDF), the distribution of SiOx coordination units and network structure. The result shows that these liquids consist of identical units SiO4, SiO5 and SiO6 and have common partial O―Si―O angle distribution. Furthermore, the major change in the diffusion mechanism under pressure is also considered and discussed

  • 85.pdf.jpg
  • Article


  • Authors: Nguyen, Thi Thanh Ha; Pham, Khac Hung (2013)

  • Diffusion mechanism and dynamics in Al2O3 liquidhave been studied via molecular dynamics simulation. Six models with different density and at temperature of 3000 K have been used to study the atomistic mechanism governing the process of the bond-breaking and bond-reformation (the transition AlOx®AlOx+1 and AlOx®AlOx-1). Calculation shows that the diffusion of particle Al is realized via the transition AlOx®AlOx±1 and the rate of transition AlOx®AlOx±1 monotonously increases with pressure. When applying pressure to liquid the diffusion mechanism changes from strong localization of transitions SiOx®SiOx±1 in the sample at ambient pressure to uniform distribution transitions SiOx®SiOx±1...

  • TL1.pdf.jpg
  • Article


  • Authors: Nguyen, Thi Thanh Ha; Nguyen, Anh Dung; Nguyen, Quang Bau; Pham, Khac Hung (2016)

  • We have studied the diffusion mechanism in network-forming liquids via molecular dynamics simulation. Two models of silica liquid at temperatures of 2600 and 3500 K have been constructed. The motion of atoms is analyzed through reactions SiOx®SiOx±1, OSiy®OSiy±1 and coordination cells. It was shown that the reactions happen not randomly in the space, but they occur more frequently with some coordination cells and bonds Si-O. This effect enhances upon lowering the temperature. The number of reactions happening in the coordination cells is strongly correlated with the mobility of CC atom. We found that there are large rigid clusters which compose of immobile atoms and exist for long tim...

  • The Microstructural Transformation and Dynamical Properties in Sodium-silicate Molecular Dynamics Simulation.pdf.jpg
  • Article


  • Authors: Nguyen, Thi Thanh Ha; Tran, Thuy Duong; Nguyen, Hoai Anh (2020)

  • Molecular dynamics simulation of sodium-silicate has been carried out to investigate the microstructural transformation and diffusion mechanism. The microstructure of sodium silicate is studied by the pair radial distribution function, distribution of SiOx (x=4,5,6), OSiy (y=2,3) basic unit, bond angle distribution. The simulation results show that the structure of sodium silicate occurs the transformation from a tetrahedral structure to an octahedral structure under pressure. The additional network-modifying cation oxide breaking up this network by the generation of non-bridging O atoms and it has a slight effect on the topology of SiOx and OSiy units. Moreover, the diffusion of netw...