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Full-Text Articles in Physical Sciences and Mathematics
Critical Point Pairs For Smectic-A* - Smectic-C* Phase Transitions., Ted Cassirer
Critical Point Pairs For Smectic-A* - Smectic-C* Phase Transitions., Ted Cassirer
Physics
Liquid crystals is a class of materials possessing properties from both solids and fluids. Similar to solids the molecules arrange themselves in some sort of order. In the liquid crystal state there are multiple phases, smectic being one of them. In a smectic liquid crystal the molecules are aranged (along $z$) in layers. Of the smectic liquid crystals there exists different phases. In the smectic-A (Sm-A) phase the avarage tilt is $0$ relative to $z$ and in the Smectic-C (Sm-A) phase the avarage tilt is non-zero relative to $z$. Normally the liquid crystal will transition between the two phases by …
Phase Transitions In Smectic Liquid Crystal Systems, John Van Atta, Josh Ziegler
Phase Transitions In Smectic Liquid Crystal Systems, John Van Atta, Josh Ziegler
Physics
Liquid crystal systems show strong responses to small changes in both temperature and electric field. Changing these conditions can result in phase shifts and other similar behaviors. We study several theoretical models of smectic liquid crystals. The ideas and notation are first developed in basic polynomial models used to describe liquid crystal systems dependent only on temperature. Specifically, smectic-C to smectic-A phase transitions are examined in a fourth-order polynomial model. The bifurcations in the nonlinear equations are shown to correspond to the phase transi- tions in the system. Similar analytic techniques are then applied to a more complex model, based …
Optical Properties Of De Vries Liquid Crystals And A Look At Ultra Thin Freely Suspended Smectic Films, Joshua P. Fankhauser
Optical Properties Of De Vries Liquid Crystals And A Look At Ultra Thin Freely Suspended Smectic Films, Joshua P. Fankhauser
Physics
Liquid crystals exist as a fourth state of matter. They are anisotropic and due to this order, they affect light that passes through them, making them ideal candidates for optical study. By employing a basic technique for measuring a liquid crystal's birefringence and tilt angle, one is able to study a number of other properties such as the electroclinic effect. In addition, smectic liquid crystals have been studied intently because of their ability to create stable ultra-thin films of quantized layer thickness. These thin films have been studied due to the fact that they are an ideal system for investigating …
Field Control Of The Surface Electroclinic Effect In Liquid Crystal Displays, Dana Hipolite
Field Control Of The Surface Electroclinic Effect In Liquid Crystal Displays, Dana Hipolite
Physics
Liquid crystals (LCs) are a fascinating class of materials exhibiting a range of phases intermediate between liquid and crystalline. Smectic LCs consist of elongated molecules arranged in a periodic stack (along z) of liquid like layers. In the smectic-A (Sm-A) phase, the average molecular long axis (director) points along z. In the smectic-C (Sm-C) phase, it is tilted relative to z, thus picking out a special direction within the layers. Typically, the Sm-A* to Sm- C* transition will occur as temperature is decreased. In chiral smectics (Sm-*A or Sm-C*) it is possible to induce director titling (i.e. the Sm-C* phase) …
Analysis Of An Unusual Liquid Crystal Phase Transition, Loni Ann Fuller
Analysis Of An Unusual Liquid Crystal Phase Transition, Loni Ann Fuller
Physics
Liquid crystals are a unique phase of matter that resemble a state between a solid and liquid. Within these properties, liquid crystal molecules have the ability to align and create layers. From this phenomenon, many electro-optical effects can be investigated, such as measuring the tilt angle between molecules at different temperatures and applied electric fields and also measuring the birefringence, which is a unique property of liquid crystals in which the index of refraction of the sample behaves differently along different axes. In order to better understand these electro- optical effects, we designed a more precise protocol of measuring this …