相关论文: Molecular dynamics simulations of the Johari-Golds…
Molecular dynamics simulations were carried out on a Lennard-Jones binary mixture of rigid (fixed bond length) diatomic molecules. The translational and rotational correlation functions, and the corresponding susceptibilities, exhibit two…
We show using molecular dynamics simulations that simple diatomic molecules in the glassy state exhibit only limited participation in the Johari-Goldstein (JG) relaxation process. That is, with sufficient cooling local reorientations are…
The heterogeneous character of the Johari-Goldstein (JG) relaxation is evidenced by molecular-dynamics simulation of a model polymer system. A double-peaked evolution of dynamic heterogeneity (DH), with maxima located at JG and structural…
We investigate the Johari-Goldstein (JG) $\beta$-relaxation process in a model metallic glass-forming (GF) material (Al90Sm10), previously studied extensively by both frequency-dependent mechanical measurements and simulation studies…
Using molecular dynamics simulations we examine the system size dependence of the fast dynamics in two model glass forming liquids, one of them a Lennard-Jones mixture for which cooperative fast relaxation has been reported. We find no…
The relaxation properties of viscous liquids close to their glass transition (GT) have been widely characterised by the statistical tool of time correlation functions. However, the strong influence of ubiquitous non-linearities calls for…
Supercooled liquids undergo complicated structural relaxation processes, which have been a long-standing problem in both experimental and theoretical aspects of condensed matter physics. In particular, past experiments universally observed…
The elusive connection between dynamics and local structure in supercooled liquids is an important piece of the puzzle in the unsolved problem of the glass transition. The Johari-Goldstein beta relaxation, ubiquitous in glass-forming…
We investigate the fast $\beta$- and Johari-Goldstein (JG) $\beta$-relaxation processes, along with the elastic scattering response of glass-forming (GF) liquids and the Boson peak, in a simulated Al-Sm GF material exhibiting a…
We presented that the relaxation of n coupling molecules in a molecular string exhibits n individual relaxation modes (RMs), each mode being characterized by a definite relaxation time and amplitude according to the string model. The n RMs…
Within the mode-coupling theory (MCT) for the evolution of structural relaxation in glass-forming liquids, correlation functions and susceptibility spectra are calculated characterizing the rotational dynamics of a top-down symmetric…
We report a molecular dynamics (MD) study of the collective dynamics of a simple monatomic liquid -interacting through a two body potential that mimics that of lithium- across the liquid-glass transition. In the glassy phase we find…
We employ an atomic-scale theory within the framework of nonaffine lattice dynamics to uncover the origin of the Johari-Goldstein (JG) $\beta$-relaxation in metallic glasses (MGs). Combining simulation and experimental data with our…
The molecular mobility of glassy and supercooled liquid states of clotrimazole is studied using broadband dielectric spectroscopy for a wide range of temperatures and frequency. The dielectric loss data of clotrimazole below T$_{g}$, do not…
We show that incoherent quasi-elastic neutron scattering (QENS) from molecular liquids reveals a two-state dynamic heterogeneity on a 1 ps timescale, where molecules are either highly confined or are free to undergo relatively large…
Strong changes in bulk properties, such as modulus and viscosity, are observed near the glass transition temperature, T_{g}, of amorphous materials. For more than a century, intense efforts have been made to define a microscopic origin for…
We propose a simple microscopic model of molecular dynamics simulation to study orientational glass in three dimensions. We present simulation results for mixtures of mildly anisotropic particles and spherical impurities. We realize fcc…
Molecular dynamics (MD) simulations are used to investigate $^1$H nuclear magnetic resonance (NMR) relaxation and diffusion of bulk $n$-C$_5$H$_{12}$ to $n$-C$_{17}$H$_{36}$ hydrocarbons and bulk water. The MD simulations of the $^1$H NMR…
Molecular dynamics simulations are performed to investigate heterogeneous dynamics in amorphous glassy materials under oscillatory shear strain. We consider three-dimensional binary Lennard-Jones mixture well below the glass transition…
In an attempt to quantitatively characterize the recently observed slow dynamics in the isotropic and nematic phase of liquid crystals, we investigate the single-particle orientational dynamics of rodlike molecules across the…