http://hdl.handle.net/20.500.12128/13055
Tytuł: | Distortion-sensitive insight into the pretransitional behavior of 4-n-octyloxy-4?-cyanobiphenyl (8OCB) |
Autor: | Rzoska, Sylwester Drozd-Rzoska, Aleksandra Mukherjee, P. K. Lopez, D. O. Martinez-Garcia, J. C. |
Słowa kluczowe: | dynamic dielectric properties; nonlinear dielectric effect |
Data wydania: | 2013 |
Źródło: | Journal of Physics: Condensed Matter, Vol. 25, no. 24 (2013), art. no. 245105 |
Abstrakt: | Results of studies of the static and dynamic dielectric properties in rod-like 4-n-octyloxy-4'-cyanobiphenyl (8OCB) with isotropic (I)–nematic (N)–smectic A (SmA)–crystal (Cr) mesomorphism, combined with measurements of the low-frequency nonlinear dielectric effect and heat capacity are presented. The analysis is supported by the derivative-based and distortion-sensitive transformation of experimental data. Evidence for the I–N and N–SmA pretransitional anomalies, indicating the influence of tricritical behavior, is shown. It has also been found that neither the N phase nor the SmA phase are uniform and hallmarks of fluid–fluid crossovers can be detected. The dynamics, tested via the evolution of the primary relaxation time, is clearly non-Arrhenius and described via τ(T) = τc(T−TC)−phgr. In the immediate vicinity of the I–N transition a novel anomaly has been found: Δτ ∝ 1/(T − T*), where T* is the temperature of the virtual continuous transition and Δτ is the excess over the 'background behavior'. Experimental results are confronted with the comprehensive Landau–de Gennes theory based modeling. |
URI: | http://hdl.handle.net/20.500.12128/13055 |
DOI: | 10.1088/0953-8984/25/24/245105 |
ISSN: | 1361-648X 0953-8984 |
Pojawia się w kolekcji: | Artykuły (WNŚiT) |
Plik | Opis | Rozmiar | Format | |
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Rzoska_Distortion_sensitive_insight.pdf | 1,6 MB | Adobe PDF | Przejrzyj / Otwórz |
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