H. Yurtseven

Bio: H. Yurtseven is an academic researcher. The author has contributed to research in topics: Liquid crystal & Phase transition. The author has an hindex of 1, co-authored 1 publications receiving 8 citations.

Landau theory of the nematic-smectic a tricritical phase transition in a binary mixture of liquid crystals

Abstract: We have developed in this study a thermodynamic model for the nematic-smectic A (NA) tricritical phase transition of a binary mixture of liquid crystals in analogy with the model for quasi fluid mixtures due to Griffiths. Using the Landau theory with a symmetrical TCP, we have predicted the critical behaviours of the nematic susceptibility, order parameter and the specific heat discontinuity in the vicinity of the TCP. Our predictions for the tricritical exponents for the order parameter and the specific heat discontinuity are those predicted by the mean field theory (β=1/4 and α=1/2) with a symmetrical TCP. Our exponent value of γ=1/2 for the nematic susceptibility does not agree with the mean field value of γ=1. Our predicted values agree with those obtained experimentally for some binary mixtures of liquid crystals. This means that the mean field model with a symmetrical TCP is capable of describing the nematic-smectic A tricritical phase transition for a symmetrical binary mixture of liquid c...

A phase diagram for ammonium halides

Abstract: In this study we have developed a mean field model to obtain the phase diagrams for NH4Cl and NH4Br. The phase diagrams obtained from our macroscopic theory are in good agreement with those obtained experimentally.

Temperature dependence of the order parameters (spontaneous polarisation and the tilt angle) at various concentrations for a mixture of SCE9+SCE10

Abstract: The smectic A- smectic C* (AC*) transition in a binary mixture of SCE9+SCE10 is studied at various concentrations of SCE9 near (x c = 012) and above x c (tricritical concentration) The temperature dependences of the spontaneous polarisation and the tilt angle (order parameters) are calculated using our mean field model with the bilinear and biquadratic couplings between these two order parameters The expressions derived from the mean field model are fitted to the experimental data from the literature and the coefficients given in the free energy are determined It is demonstrated that our mean field model explains the observed mean field to tricritical behaviour in SCE9+SCE10

A phase diagram near the NAC* point in liquid crystals

Abstract: We study here a mean field model to obtain the phase diagram (concentration versus temperature) near the NAC* point in a binary mixture of liquid crystal. We have fitted our phase line equations to the experimental data for the mixture of SCE9 + SCE10 liquid crystals. We deduce from our analysis that there should exist a tricritical point close to the NAC* point on the AC* phase line.

Calculation of the T-X phase diagram for a mixture of liquid crystals

Abstract: In this study we calculate the T-X phase diagram for a mixture of liquid crystals. In this calculation we use a mean field theory. We fit our calculated phase line equations to the experimental data from the literature. There is a very good agreement between our calculated and the experimentally observed phase diagram.