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Optical Microscopy. Robert Krouch & Farrell Rogers. National High Magnetic Field Lab Florida State University Tallahassee, FL RET Summer 2003. Microscopy is Broad. Research with the use of the Microscope Our area of research focused on Liquid Crystal Phase changes. States of Matter.
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Optical Microscopy Robert Krouch & Farrell Rogers National High Magnetic Field Lab Florida State University Tallahassee, FL RET Summer 2003
Microscopy is Broad • Research with the use of the Microscope • Our area of research focused on Liquid Crystal Phase changes
States of Matter Solid Liquid crystal “fourth state of matter” Liquid Gas
What is a Liquid Crystal? Liquid Crystal – a thermodynamic stable phase characterized by anisotropy of properties without the existence of a 3-dimensional crystal lattice – generally lying between the solid and isotropic(“liquid”) phase.
Isotropic Liquids and gases (uniform properties in all directions). vs.Anisotropic Liquid Crystals have orientational order
Transition Phases There are 2 basic phases Nematic & Smectic Anisotrpic substances may go through several Liquid Crystal Phases
Smectic Phase Characteristics • Form at lower temperatures • Form well defined layers that slide over one another • Tend to be 2-dimensional
Nematic PhaseCharacteristics • Molecules are oriented in loose parallel lines • Occurs at higher temperatures than smectics • Has many subdivisions, i.e. cholesterics, thermotropic, etc
Temperature Profile andMicroscope Imaging Use the Nikon DXM 1200 Camera and Nikon Opti-Shot PDL to locate best location of specimen. Once the heater reaches the desired temperature, you are ready to begin your experiment.
Now we wait and wait and wait
Adobe PhotoshopAdobe Premiere All the pictures are imported into Adobe Premiere. At this point all the pictures are viewed in a running sequence to identify phase transitions.
Mathematical equations are used to find the temperatures at which the matter changes states CE-3 Sample 1
AVI of CE-3 With an abundance of pictures at the transition points, Adobe Acrobat is used to create an AVI of the crystallization.
Birefrigence and polarized lenses allow the transitions of p-hexyloxybenzylidene to be very pleasing to the eye.
LCD Application The Nematic phase is most commonly used in Liquid Crystal Displays (LCD)
Thank you Mike Davidson John Griffin Dr. Pat Dixon Ms. Gina LaFrazza-Hickey The CIRL Staff