MRS Meetings and Events

 

DS01.05.10 2022 MRS Fall Meeting

Thermodynamic Assessment of Heat Capacity and Entropy in Fragile Glasses

When and Where

Nov 29, 2022
8:00pm - 10:00pm

Hynes, Level 1, Hall A

Presenter

Co-Author(s)

Colby Stoddard1,Hillary Smith1

Swarthmore College1

Abstract

Colby Stoddard1,Hillary Smith1

Swarthmore College1
The bulk metallic glasses Pt80-xCuxP20 where 14 < x < 27 exhibit high fragility and a sharp glass transition. This results in a large excess entropy of the liquid phase over the crystalline phase. We used a combination of differential scanning calorimetry (DSC) and inelastic neutron scattering (INS) measurements to characterize the thermodynamics in these Pt-Cu-P glasses across a range in compositions. The isobaric heat capacity and vibrational entropy of the amorphous solid, crystalline solid, and supercooled liquid phases are assessed with DSC and INS, respectively. These data are used to calculate the difference in enthalpy, total entropy, vibrational entropy and Gibbs free energy between the solid and liquid phase. A significant increase in heat capacity is observed at the glass transition, but this does not correspond to a large change in the vibrational entropy. Insights into the effect of fragility on these thermodynamic parameters will be discussed.

Keywords

calorimetry | specific heat | thermodynamics

Symposium Organizers

Wenhao Sun, University of Michigan
Alexandra Khvan, National Research Technological University
Alexandra Navrotsky, Arizona State University
Richard Otis, NASA Jet Propulsion Laboratory

Publishing Alliance

MRS publishes with Springer Nature