Sökning: "crystals"

Visar resultat 1 - 5 av 669 avhandlingar innehållade ordet crystals.

1. 1. Building crystals out of crystals : Synthesis, structure and magnetic properties of iron oxide nanoparticles and self-assembled mesocrystals

   Författare :Erik Wetterskog; Lennart Bergström; Markus Niederberger; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; iron oxide; nanoparticle; synthesis; self-assembly; characterization; electron microscopy; scattering; magnetic properties; Materials Chemistry; materialkemi;

   Sammanfattning : This thesis is focused on the fabrication and characterization of self-assembled arrays of magnetic iron oxide (Fe3O4, γ-Fe2O3 and Fe1-xO) nanoparticles. The synthesis of spherical and cubic iron oxide nanocrystals, with sizes between 5 and 30 nm and narrow size distributions, is demonstrated, along with a rigorous morphological characterization of the cubic nanoparticles. LÄS MER

3. 2. Complex Oxide Photonic Crystals

   Författare :Dzmitry Dzibrou; Alex Grishin; Peter Lazor; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Photonic crystals; magneto-optical effects; refractive index; iron garnet; Optics; Optik;

   Sammanfattning : Microphotonics has been offering a body of ideas to prospective applicationsin optics. Among those, the concept of photonic integrated circuits (PIC’s) has recently spurred a substantial excitement into the scientific community. Relisation of the PIC’s becomes feasible as the size shrinkage of the optical elements is accomplished. LÄS MER

4. 3. InP-based photonic crystals : Processing, Material properties and Dispersion effects

   Författare :Audrey Berrier; Srinivasan Anand; Alfred Forchel; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Photonic crystals; indium phosphide; photonic bandgap; Bloch modes; slow light; dispersion; coupled cavity waveguides; chemically assisted ion beam etching; lag effect; cavities; optical losses; carrier transport; carrier lifetimes; negative refraction; photonic bandstructure; Physics; Fysik;

   Sammanfattning : Photonic crystals (PhCs) are periodic dielectric structures that exhibit a photonic bandgap, i.e., a range of wavelength for which light propagation is forbidden. The special band structure related dispersion properties offer a realm of novel functionalities and interesting physical phenomena. LÄS MER

5. 4. Liquid Crystals in Guided Wave Optics

   Författare :Giusy Scalia; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; antiferroelectric liquid crystals; fully-leaky guided mode; ortho-conics; waveguide; liquid crystals; anisotropy;

   Sammanfattning : Liquid crystals are unique optical materials due to their large effective electrooptic and opto-optic coefficients. Currently, liquid crystals are primarily used in flat-panel dis-plays, but there is also an increasing number of nondisplay applications requiring new types of devices employing materials with unique optical properties. LÄS MER

7. 5. Electronic addressing of ferroelectric liquid crystals

   Författare :Tomasz Matuszczyk; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; multiplexing; smectic; displays; ferroelectricity; black mask; polarization; mesophases; light modulators; surface-stabilized structure; light valve; dielectric anisotropy; polarized light; liquid crystals; chirality; ferroelectric liquid crystals; dither;

   Sammanfattning : .... LÄS MER