TY - JOUR
T1 - Thermodynamic features and enthalpy relaxation in a metal-organic framework glass
AU - Zhou, Chao
AU - Stepniewska, Malwina
AU - Longley, Louis
AU - Ashling, Christopher W.
AU - Chater, Philip A.
AU - Keen, David A.
AU - Bennett, Thomas D.
AU - Yue, Yuanzheng
PY - 2018/6/25
Y1 - 2018/6/25
N2 - In this work, we explore the thermodynamic evolution in a melt-quenched metal-organic framework glass, formed from ZIF-62 upon heating to the melting point (T
m), and subsequent enthalpy relaxation. The temperature dependence of the difference in Gibbs free energy between the liquid and crystal states of ZIF-62 in the temperature range from the glass transition temperature (T
g) to T
m is found to be weaker than those of other types of glasses, e.g., metallic glasses. Additionally, we find that the stretched exponent of the enthalpy relaxation function in the glass varies significantly (β = 0.44-0.76) upon changing the extent of sub-T
g annealing, compared to metallic and oxide glasses with similar T
gs, suggesting a high degree of structural heterogeneity. Pair distribution function results suggest no significant structural changes during the sub-T
g relaxation in ZIF-62 glass.
AB - In this work, we explore the thermodynamic evolution in a melt-quenched metal-organic framework glass, formed from ZIF-62 upon heating to the melting point (T
m), and subsequent enthalpy relaxation. The temperature dependence of the difference in Gibbs free energy between the liquid and crystal states of ZIF-62 in the temperature range from the glass transition temperature (T
g) to T
m is found to be weaker than those of other types of glasses, e.g., metallic glasses. Additionally, we find that the stretched exponent of the enthalpy relaxation function in the glass varies significantly (β = 0.44-0.76) upon changing the extent of sub-T
g annealing, compared to metallic and oxide glasses with similar T
gs, suggesting a high degree of structural heterogeneity. Pair distribution function results suggest no significant structural changes during the sub-T
g relaxation in ZIF-62 glass.
UR - http://www.scopus.com/inward/record.url?scp=85049826080&partnerID=8YFLogxK
U2 - 10.1039/c8cp02340a
DO - 10.1039/c8cp02340a
M3 - Journal article
SN - 1463-9076
VL - 20
SP - 18291
EP - 18296
JO - Physical Chemistry Chemical Physics
JF - Physical Chemistry Chemical Physics
IS - 27
ER -