(a) Loss part ε″ of the dielectric permittivity of toluene/PCB54 mixtures for different mole fractions x at T = 118 K (adapted from Ref. 17 ) including data of neat toluene from Ref. 11 . (b) Dielectric loss for different mole fractions of toluene in picoline (T ≈ 116 K). (c) Concentration dependence of the glass transition temperature T g determined from DSC measurements for both mixtures. Lines serve as guide for the eye, T g of neat PCB54 from Ref. 17 .
(a) Solid-echo spectra of toluene-d3 in PCB54 for different mole fractions x at similar absolute temperature T = (104 ± 2) K, each spectrum recorded for inter-pulse delays of t p = 20 μs (solid red line) and t p = 200 μs (dashed black line). (b) Relative spectral intensity at zero frequency with respect to the singularities R(t p = 200 μs) for different concentrations of toluene-d3 in PCB54 as a function of temperature. All lines serve as guide for the eye. Inset sketches the solid-echo pulse sequence.
(a) Normalized inter-pulse dependence of the R(t p ) value for different mole fractions of toluene-d5 in PCB54 at T = 107 K. The lines represent fits via Eq. (1) with concentrations independent values of τ, β. (b) Same representation for mixtures of toluene and picoline (T = (105 ± 5) K), including measurements on the type-A component (red) in its neat form and from a deuterated picoline/protonated toluene mixture.
Concentration dependent fraction ξ of toluene molecules exhibiting a β-process in mixtures with PCB54 (full symbols) and picoline (open symbols), the line serves as guide for the eye. The results from the ⟨T 1⟩ analysis are obtained from B(x)/B(1) (cf. Eq. (8) ) and have not been scaled.
(a) Stimulated echo decay curves (F cos(t e ; t m )) of x = 0.77 and 0.59 toluene-d5 in PCB54 for different evolution times recorded at 97 K in comparison with data of neat toluene. 18 The full line represents a fit via Eq. (3) , for the dashed line see text. (b) Concentration dependence of the amplitude at 97 K, a clear trend is seen for concentrations below x = 0.77. Lines serve as guide for the eye. (c) Concentration dependence of the geometrical factor p(t e ), line serves as guide for the eye. The sketch above (c) demonstrates the employed pulse sequence.
(a) Average spin-lattice relaxation times ⟨T 1⟩ for mixtures of toluene-d5 with PCB54 (full symbols) and picoline (open symbols). The dashed lines at low temperatures represent Arrhenius fits to ⟨T 1⟩ for T<T g (cf. Eq. (8) ). Data of neat toluene adapted from Refs. 10 and 29 . (b) Normalized magnetization relaxation function for samples with different concentrations of toluene-d5 in PCB54 recorded at 97 K. Whereas the initial slope appears approximately concentration independent, the long time “tail” of the curves becomes more pronounced at low concentrations.
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