24
K. Adrjanowicz
Keywords Crystallization · Glass-forming liquids · High-pressure · Dielectric
spectroscopy · Molecular mobility · Thermodynamic driving force
Abbreviations
τ α
α-Relaxation time
n
Avrami parameter
CNT
Classical nucleation theory
t 1/2
Crystallization half-time
k
Crystallization rate constant
CDT diagram Continuous-decompression-transformation diagram
CHT diagram Continuous-heating-transformation diagram
T
Degree of undercooling (T m −T )
DS
Dielectric spectroscopy
T g
Glass transition temperature
U
Growth rate
t ind
Induction time
σ
Liquid/crystal interface energy
T m
Melting temperature
ε N
Normalized dielectric permittivity
I
Nucleation rate
p
Pressure
PC
Propylene carbonate
T
Temperature
τ #
The nucleation time lag
μ
Thermodynamic driving force towards crystallization
TPT diagram Time-pressure-transformation diagram
TTT diagram Time-temperature-transformation diagram
1 Introduction
When a liquid is cooled below the melting temperature, it will solidify and form a
crystal of a regular, well-defined array of atoms/molecules. However, sometimes it
can be also supercooled and with lowering temperature further it enters the glassy
state. The liquid is metastable in the supercooled regime and tends to crystallize. This
is a fundamental problem which scientists have to deal with for decades, particularly
if they want to focus on the glass transition phenomenon or the practical advantages
given by the glassy state [1–3]. Since crystallization and glass-formation are two
sides of the same coin, by understanding what governs crystallization in supercooled
liquids, we can learn how to make good glass-formers.