Sökning: "Materialfysik"

Visar resultat 1 - 5 av 133 avhandlingar innehållade ordet Materialfysik.

1. 1. Silicon Nanowires for Biomolecule Detection

   Författare :Niklas Elfström; Jan Linnros; Mark Reed; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Material physics with surface physics; Materialfysik med ytfysik;

   Sammanfattning : Starting from silicon on insulator (SOI) material, with a top silicon layer thickness of 100 nm, silicon nanowires were fabricated in a top down approach using electron beam (e-beam) lithography and subsequent eactive ion etching (RIE) and oxidation. Nanowires as narrow as 30 nm could be achieved. LÄS MER

3. 2. Phthalocyanine interfaces : the monolayer region

   Författare :Pål Palmgren; Mats Göthelid; Mats Fahlman; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; phthalocyanine; III-V semiconductor; transition metal oxides; adsorption; self-assembly; Material physics with surface physics; Materialfysik med ytfysik;

   Sammanfattning : Organic molecules adsorbed on inorganic substrates are the topics of interest in this thesis. Interfaces of this kind are found in dye sensitized solar cells that convert solar energy to electricity, a promising environmentally friendly energy source which might provide a route to replace fossil fuels. LÄS MER

4. 3. Resistivity and the solid-to-liquid transition in high-temperature superconductors

   Författare :Beatriz Espinosa Arronte; Magnus Andersson; Charles Simon; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; high-temperature superconductors; vortex dynamics; vortex solid-to-liquid transition; critical scaling; glass transition; Bose glass; heavy-ion irradiation; YBCO; Tl2Ba2CaCu2O8 d; oxygen deficiency.; Condensed matter physics; Kondenserade materiens fysik;

   Sammanfattning : In high-temperature superconductors a large region of the magnetic phase diagram is occupied by a vortex phase that displays a number of exciting phenomena. At low temperatures, vortices form a truly superconducting solid phase which at high temperatures turns into a dissipative vortex liquid. LÄS MER

5. 4. Ceria-based nanocomposite electrolyte for low-temperature solid oxide fuel cells

   Författare :Ying Ma; Mamoun Muhammed; Peter Lund; KTH; []
   Nyckelord :;

   Sammanfattning : Solid oxide fuel cells (SOFCs) have attracted much attention because of their potential of providing an efficient, environmentally benign, and fuel-flexible power generation system for both small power units and for large scale power plants. However, conventional SOFCs with yttria-stabilized zirconia (YSZ) electrolyte require high operation temperature (800-1000°C), which presents material degradation problems, as well as other technological complications and economic obstacles. LÄS MER

7. 5. Spin momentum transfer effects for spintronic device applications

   Författare :Yan Zhou; Johan Åkerman; Daniel E. Bürgler; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Spin Torque Oscillator; Giant Magnetoresistance; Tunneling Magnetoresistance; Magnetism; Magnetism;

   Sammanfattning : The recent discovery that a spin-polarized current can exert a large torque on a ferromagnet, through direct transfer of spin angular momentum, offers the possibility of electrical current controlled manipulation of magnetic moment in nanoscale magnetic device structures. This so-called spin torque effect holds great promise for two applications, namely, spin torque oscillators (STOs) for wireless communication and radar communication, and spin transfer torque RAM (STT-RAM) for data/information storage. LÄS MER