On the energy landscape at the glass transition

نویسندگان

  • Ulrich Buchenau
  • U. Buchenau
چکیده

A recent hypothesis claims that the glass transition itself, though it is a very pronounced relaxation peak, is no separate relaxation process at all, but is just the breakdown of the shear modulus due to the weak elastic dipole interaction between all the quasi-independent relaxation centers of the glass. Two derivations are considered, one of them in terms of a breakdown of the shear modulus and the second in terms of a divergence of the shear compliance. Mechanical relaxation data from the literature for vitreous silica, glycerol, polymethylmethacrylate and polystyrene are found to be consistent with the first hypothesis. PACS numbers: 64.70.Pf

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Statistical mechanics of correlated energy landscape models for random heteropolymers and proteins

We study the role of correlations in the energy landscape of heteropolymers and proteins, specifically their role in the glass transition in random heteropolymers and the folding transition in minimally frustrated proteins. In the context of the glass transition, a correlated landscape results in a more gradual freezing into basins of extensive entropy, while not completely destroying the first...

متن کامل

Ideal glass transitions in thin films: An energy landscape perspective

Thomas M. Truskett & Venkat Ganesan Department of Chemical Engineering and Institute for Theoretical Chemistry, The University of Texas at Austin, Austin, TX 78712. Abstract We introduce a mean-field model for the potential energy landscape of a thin fluid film confined between parallel substrates. The model predicts how the number of accessible basins on the energy landscape and, consequently,...

متن کامل

بررسی دینامیک ملکولی شیشه فلورید Zr/Ba/Na در فشار جو و 4 گیگاپاسکال

  A constant volume, atmospheric pressure Zr/Ba/Na fluoride glass has been simulated by molecular dynamics with the limitations of the Born-Mayer-Huggins potentials, used previously and resulting in high simulation pressures, having been overcome. The simulated structure of this glass as well as its activation energy for diffusion are in very good agreement with those experimentally observed. T...

متن کامل

A conformal solution theory for the energy landscape and glass transition of mixtures

We apply conformal solution theory and extend to mixtures a recently derived equation of state for glass-forming liquids. The equation of state is based on the statistical properties of the multidimensional potential energy surface as a function of a macroscopic system’s degrees of freedom (energy landscape), and allows the calculation of an ideal glass transition locus, along which the configu...

متن کامل

Determination of the activation energy of crystallization based up on Ozawa and Kissinger formalisms and thermal stability of V2O5-NiO- TeO2 glasses by differential scanning calorimetry (DSC)

In the present research work, (60-x)V2O5-xNiO-40TeO2 amorphous bulk compositions with different molar percentages of 0≤x≤20 mol%, were prepared by well-known  rapid melt-quenching method. Differential scanning calorimetry (DSC) at different heating rates (φ) was used to thermal analyze and to obtain more insight in to the thermal stability, glass forming tendency and so calorimetric characteris...

متن کامل

2 Energy landscape - a key concept in the dynamics of glass formers

There is a growing belief that the mode coupling theory is the proper microscopic theory for the dynamics of the undercooled liquid above and around a critical temperature T c. In addition, there is some evidence that the system leaves the saddlepoints of the energy landscape to settle in the valleys at this critical temperature. Finally, there is a microscopic theory for the entropy at the cal...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2004