| Autor: |
Manal Poovingal, N N, Shahin Thayyil, Mohamed, Afzal, Aboothahir, Govindaraj, G |
| Zdroj: |
Indian Journal of Physics; Jun2022, Vol. 96 Issue 7, p1991-1999, 9p |
| Abstrakt: |
Dielectric response and thermal behavior of an orientationally disordered organic crystal cyclobutanol were critically investigated with differential scanning calorimetry and broadband dielectric spectroscopy (10−2 to 107 Hz) from the deep glassy crystalline state to its melting temperature. The effort was made to understand the relaxation dynamics of plastic crystals of diverse characteristics, which lack translational degrees of freedom and to explore features of different transition and to get a comprehensive understanding on glass-forming dynamics. Information about polymorphism, solid–solid phase transitions, their kinetic freezing, structural and secondary relaxation were explored. The structural relaxation showed non-Arrhenius T-dependence and non-Debye features in the frequency domain. The resolved secondary relaxation in cyclobutanol was identified to be intermolecular or Johari–Goldstein (JG) relaxation from coupling model predictions. The investigated sample was revealed as an intermediate system in Angell's criteria of strong–fragile classification. The data on cyclobutanol filled the gap for attaining a comprehensive picture on low molecular cyclic alcohols, where Tg showed a progressive increase with molecular weight, while the steepness index exhibited a smooth switch over from fragile to strong behavior. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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