Sökning: "periodic structure"

Visar resultat 11 - 15 av 165 avhandlingar innehållade orden periodic structure.

1. 11. Single-crystal Mo/V superlattices : growth, structure, and hydrogen uptake

   Författare :Jens Birch; Jan-Erik Sundgren; Bruce M Clemens; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Fundamental studies concerning the growth, structural characterization and hydrogen uptake of single-crystal (00 l )-oriented Mo/V superlattices have been performed. The superlattices were grown by dual-target magnetron sputtering in pure Ar-atmosphere < 6·10-3 Torr on (001)-oriented MgO substrates. LÄS MER

3. 12. Integrated Lumped Element and Ferroelectrically Tunable Microwave Components

   Författare :Dan Kuylenstierna; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; lumped; Passive element; metamaterial; periodic structure;

   Sammanfattning : This thesis treats the development of passive circuits for increased integrationlevel in microwave front-ends. The subject is approached from twodifferent directions. On the one hand, emerging materials for microwaveintegrated circuits are studied. On the other hand, novel circuit topologiesare synthesized. LÄS MER

4. 13. Lateral Superlattices in Commensurate Magnetic Fields: Electronic Structure, Transport and Optical Properties

   Författare :Egidijus Anisimovas; Matematisk fysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; tunneling; Physics; collective excitations; optical absorption; quantum Hall effect; electronic structure; two-dimensional electron systems; lateral superlattices; Electromagnetism; Fysik; optics; acoustics; Elektromagnetism; optik; akustik; Fysicumarkivet A:2001:Anisimovas;

   Sammanfattning : The present thesis is devoted to the theoretical study of two-dimensional electron systems moving in a modulated lateral periodic potential and a competing perpendicular magnetic field. The three introductory chapters offer a brief exposition of the basic issues in this area -- the description of the electron motion in a prependicular magnetic field, the group of magnetic translations and the commensurability phenomena -- at an elementary level. LÄS MER

5. 14. Controlling Electronic and Geometrical Structure of Honeycomb-Lattice Materials Supported on Metal Substrates : Graphene and Hexagonal Boron Nitride

   Författare :Nikolay Vinogradov; Nils Mårtensson; Karsten Horn; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; graphene; h-BN; electronic structure; adsorption; doping; nano-templates; PES; NEXAFS; LEEM; STM; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

   Sammanfattning : The present thesis is focused on various methods of controlling electronic and geometrical structure of two-dimensional overlayers adsorbed on metal surfaces exemplified by graphene and hexagonal boron nitride (h-BN) grown on transition metal (TM) substrates. Combining synchrotron-radiation-based spectroscopic and various microscopic techniques with in situ sample preparation, we are able to trace the evolution of overlayer electronic and geometrical properties in overlayer/substrate systems, as well as changes of interfacial interaction in the latter. LÄS MER

7. 15. Analysis of Planar and Circular Cylindrical Multilayer Structures with Application to Soft and Hard Surfaces

   Författare :Zvonimir Sipus; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; antennas; periodic surfaces; integral equations; approximate boundary conditions; soft and hard surfaces; Green s functions; corrugated surfaces; moment method; periodic metal strips; multilayer structures; EFIE; microstrip antennas; spectral domain analysis; group representation theory; strip scatterers;

   Sammanfattning : This thesis deals with the analysis of planar and circular cylindrical multilayer structures, such as strip-loaded dielectric layers, corrugated surfaces and microstrip antennas. In particular, we study corrugations and strip-loaded grounded dielectric slabs when they are used to realize soft and hard surfaces. LÄS MER