arXiv subjects

Sudha Srivastava

Publications and source records attributed to Sudha Srivastava.

3 recordsLinked to original sources

arXiv2001

Transport coefficients at Metastable Densities from models of Generalized Hydrodynamics

In the present work we compute the enhancement in the long time transport coefficients due to correlated motion of fluid particles at high density. The fully wave vecor dependent extended mode coupling model is studied with the inclusion of an additional slow variable of the defect density for the amorphous system. We use the extremely slow relaxation of the density correlation function observed in the light scattering experiments on colloids to estimate the input parameters for the model The ratio of long time to short time diffusion coefficient is studied around the the peak of the structure factor.

cond-mat.stat-mech↗

arXiv2001

Fragility and Boson Peak formation in a Supercooled Liquid

We analyze results for the Boson Peak from the neutron time of flight spectroscopy data on Ge-As-Se, and Raman spectra data on m-TCP and OTP, using a recent mode coupling model that takes into account the coupling of density fluctuations with vibrational modes in presence of defects in the supercooled state. From the experimental results for different materials we observe that for more fragile systems characterized by increasing fragility parameter m, a slower relaxation of the defect-density correlation is needed to give rise to the observed peak in the spectra.

cond-mat.stat-mech↗

arXiv2001

Temperature dependence of the Power law exponent of relaxation in a supercooled Liquid

The dynamics of Lennard-Jones fluid is studied through extended mode coupling theory (MCT) with the inclusion of the slow mode of defect density. Inclusion of defect density facilitates the liquid like state for temperatures much lower than predicted from ideal MCT. From the present model the temperature dependence of the power law exponent is obtained at a {\em constant pressure}. We have also computed the wave number dependence of the power law exponent.

cond-mat.stat-mech↗