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Sıvı Kristaller ve Faz Geçişleri

Liquid Crystals and Phase Transitions

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Abstract (2. Language): 
Transition from solid phase to isotropic liquid phase is not been suddenly, it is been passing from interval phases. These interval phases are smectic, cholesteric and nematic liquid crystal phases. Molecules of liquid crystals indicate orientational order and positional disorder. With increasing temperature, solid-nematic and nematic-isotropic phase transitions are obtained. Using the modified Pople and Karasz model, the variation of order parameters with temperature, solid-nematic and nematic-isotropic liquid phase transitions and theoretical phase diagrams are studied.
Abstract (Original Language): 
Katı fazdan izotropik sıvıya geçiş birden bire olmamakta, bazı ara fazlardan geçerek izotropik sıvı meydana gelmektedir. Bu ara fazlar smektik, kolesterik ve nematik sıvı kristal fazlardır. Sıvı kristallerin molekülleri yönelimde düzenli fakat konumda düzensizdirler. Sıcaklığın artırılması ile katı-nematik ve nematik-izotropik sıvı faz geçişleri elde edilmektedir. Modife Pople ve Karasz modeli kullanılarak düzen parametrelerin sıcaklıkla değişimi, katı-nematik ve nematik-izotropik sıvı faz geçişleri ve teorik faz diyagramları incelendi.

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