https://doi.org/10.1140/epje/s10189-024-00436-5
Regular Article
Calorimetric, optical and dielectric measurements on two Schiff’s based liquid crystalline materials exhibiting multiple phase transitions
1
Department of Physics, University of North Bengal, 734013, Siliguri, Darjeeling, India
2
Department of Physics, Seva Bharati Mahavidyalaya, 721507, Jhargram, West Bengal, India
3
Ghani Khan Choudhury Institute of Engineering and Technology, 732141, Maligram, West Bengal, India
Received:
30
November
2023
Accepted:
29
May
2024
Published online:
24
June
2024
We report high-resolution calorimetric, optical and dielectric studies on two Schiff’s based liquid crystalline materials, 4O.5 and 5O.5, which exhibit multiple phase transitions. The study goes beyond the commonly studied isotropic-to-nematic (I–N) and nematic-to-smectic A (N–SmA) phase transitions and explores higher-order smectic phase transitions. The critical exponent, α values, for different phase transitions has been explored. For the I–N, N–SmA, SmA–SmC, SmC–SmF, SmF–CrG and SmB–CrG transitions, α values close to 0.5 and amplitude ratios A−/A+ ~ 1.6 and D−/D+ ~ 1 indicate a first-order nature. Notably, for the SmA–SmB transition, although α (≈ 0.64) is larger than the tricritical value of 0.5, A−/A+ ~ 1.2 and D−/D+ ~ 1, and the study reports an order parameter critical exponent (β) of 0.26 ± 0.002, which supports a tricritical nature for this transition. Importantly, the ratios of A−/A+ and D−/D+ are found to have similar values across all three-measurement methods, indicating consistency and agreement among these methods.
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© The Author(s), under exclusive licence to EDP Sciences, SIF and Springer-Verlag GmbH Germany, part of Springer Nature 2024. Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
