128
M. Jasiurkowska-Delaporte
previously [31, 32]. Two relaxation processes denoted as II and III (Fig. 4c) were
found in the Cr2 phase.
The temperature dependencies of the relaxation rates of all processes revealed
for 5P-EtFLEt-P5 and 5P-Am*FLAm*P5 in the low-frequency regime are given in
Fig. 5. The temperature dependence of the α-relaxation rate (1/τ α ) is well described
by the empirical Vogel–Fulcher–Tammann (VFT) equation
τ α = τ ∞ exp
D f T 0
T − T 0
(8)
where τ ∞ is the so-called pre-exponential factor, D f is a constant corresponding to socalled fragility index m f , i.e., the measure of the response of glass-forming systems to
temperature changes, and T 0 denotes the Vogel temperature. The VFT fit parameters
are reported in Table 2. The m f and D f parameters are related to each other by m f = 16
Fig. 5 Thermal activation plots of the structural α and secondary (β and γ ) relaxation processes
for 5P-EtFLEt-P5 (open symbols) and 5P-Am*FLAm*P5 (full symbols). The Roman numerals (I,
II, III) denote relaxation processes in the crystalline phases Cr1 and Cr2 of 5P-Am*FLAm*P5. The
inset presents the temperature dependence of dielectric strength ε α of the α-processes. Data were
taken from Refs. [20, 30] with permission ([20] Copyright © 2018 American Chemical Society and
[30] kind permission of The European Physical Journal (EPJ))
M. Jasiurkowska-Delaporte
previously [31, 32]. Two relaxation processes denoted as II and III (Fig. 4c) were
found in the Cr2 phase.
The temperature dependencies of the relaxation rates of all processes revealed
for 5P-EtFLEt-P5 and 5P-Am*FLAm*P5 in the low-frequency regime are given in
Fig. 5. The temperature dependence of the α-relaxation rate (1/τ α ) is well described
by the empirical Vogel–Fulcher–Tammann (VFT) equation
τ α = τ ∞ exp
D f T 0
T − T 0
(8)
where τ ∞ is the so-called pre-exponential factor, D f is a constant corresponding to socalled fragility index m f , i.e., the measure of the response of glass-forming systems to
temperature changes, and T 0 denotes the Vogel temperature. The VFT fit parameters
are reported in Table 2. The m f and D f parameters are related to each other by m f = 16
Fig. 5 Thermal activation plots of the structural α and secondary (β and γ ) relaxation processes
for 5P-EtFLEt-P5 (open symbols) and 5P-Am*FLAm*P5 (full symbols). The Roman numerals (I,
II, III) denote relaxation processes in the crystalline phases Cr1 and Cr2 of 5P-Am*FLAm*P5. The
inset presents the temperature dependence of dielectric strength ε α of the α-processes. Data were
taken from Refs. [20, 30] with permission ([20] Copyright © 2018 American Chemical Society and
[30] kind permission of The European Physical Journal (EPJ))