Dissertation > Excellent graduate degree dissertation topics show

The structure and magnetic properties of 3d metal film

Author: YinLiFeng
Tutor: JinXiaoFeng
School: Fudan University
Course: Condensed Matter Physics
Keywords: Uniaxial anisotropy Martensite Diffraction spots Curie temperature Metal film Low energy electron diffraction Stress anisotropy Magnetic Properties Molecular beam epitaxy Laboratory equipment
CLC: O484.4
Type: PhD thesis
Year: 2006
Downloads: 213
Quote: 2
Read: Download Dissertation

Abstract


Surface and ultrathin magnetism are frontier and hot topics in research field of magnetism. During the past two decades, with the development of experiment and theory, a great achievement has been made in artificial low dimensional magnetic system. The deeply understanding is not only for the interest of fundamental research, but also is the groundwork of the most exciting challenge area in nanotechnology: spintronics.In this thesis, I mainly introduce 4 works during these 5 years as PH. D. student: 1. Why Permalioy is so soft? 2. Kinetics of martensitic transformation of Fe on Cu(001). 3. LEED pattern of bcc Ni on GaAs(001). 4. The mechanism of uniaxial anisotropy in Fe on GaAs(001).1. A new Permalloy single crystalline phase with body-centered-cubic (bcc) structure has been achieved on GaAs(001) by molecular beam epitaxy. Its magnetism, Curie temperature and magnetic anisotropy are determined experimentally, and compared to those of conventional face-centered-cubic (fcc) Permalloy. Unexpectedly the vanishing magnetic cubic anisotropy in Permalloy is found to be independent of its atomic structure but depends only upon the stoichiometry of Fe and Ni in the Fex Ni1-x alloy. This new observation is further investigated and confirmed by first principles electronic band calculations, which helps to understand the long-standing issue why Permalloy should be a soft magnet.2. The martensitic transformation of Fe on Cu (001) as a function of temperatures has been investigated in situ and in real time by variable temperature scanning tunnelling microscope. The result shows the whole process how the martensitic phase nucleates and evolves on the nanometer scale as the temperature decreases. It is found that the surface atomic steps together with the cooling speed play an important role in determining the kinetics of the martensitic transformation.3. The morphology of bcc Ni on GaAs(001) at different thickness is investigated by STM and LEED, and compared with bcc Fe on GaAs(001). Bcc Ni is found to be Volmer-Weber growth mode, however with small morphology roughness before 7ML, and 1×1 LEED pattern is achieved at this rigion. After that, the increasing roughness should take the response of LEED pattern disappearance.4. By comapring Fe on GaAs(001) and InAs(001) system, we find the magnetic uniaxial anisotropy origins from the magnetoelastic effects due to interface strain anisotropy, and anisotropic strain relaxation will also influence the magnetic uniaxial anisotropy.

Related Dissertations

  1. Preparation and Electrocaloric Effect of BaxSr1-xTiO3 Ferroelectric Thin Films,TB383.2
  2. 1,3 - propanediamine shrink o-vanillin 3d-4f heteronuclear bimetallic complexes synthesis, structure and properties of,O627.3
  3. First-principles Study on Magnetic and Optical Properties of Rutile TiO2,O614.411
  4. High-strength low-alloy steel weld metal microstructure and properties of,TG174.4
  5. Carbon steel liquid plasma electrolytic carbonitriding research,TG156.8
  6. Ku-band high power microwave NiZn ferrite material properties and simulation applications,TM277
  7. Vestigation on Magnetic Entropy Change Properties of LaCeFeSi and NiMnSn Magnetocaloric Materials,O482.5
  8. Pressure Extrusion Formation and Soft Magnetic Properties Study of Composite Magnetic Powder Cores,TF124.39
  9. Study on High Silicon Coating by Dc-Plasma Jet Surface Metallurgy,TG174.4
  10. The Research on the Non-equilibrium Microstructure of Ti6Al4V Alloy,TG146.23
  11. Structure and Magnetic Properties of FeCuNb (Ti) SiB,TG139.8
  12. Research on Transformation Mechanism of Bainite and Martensite in Steel of 35CrMo Ect.,TG111.5
  13. Preparation and Characterization of Noble Metals and Their Alloys / Carbon Nanotube Composites,TB383.1
  14. Preparation and Application of Manganese-Zinc Ferrite Nanoparticles,TB383.1
  15. Electrodeposited Rare Earth-Iron Group Magnetic Films and Their Magnetism,TB383.2
  16. Synthesis, crystal structure and magnetic properties of the cyano-bridged bimetallic complexes,O621.1
  17. Research on Electrical and Magnetic Properties of Composite Garnet Ferrite Sintered at Low-temperature,TQ138.11
  18. Research on Transparent Conductive Film of ZnO/metal/ZnO Structure,TM24
  19. Structure and Properties of InAs/GaSb Strain Superlattice Materials,TN304.055
  20. Stydu on TbCu7-Type Sm-Co Matrix Ribbon Magnets,O482.5
  21. The Research of Mn-Al-C Type Magnetic Alloys,TM271

CLC: > Mathematical sciences and chemical > Physics > Solid State Physics > Thin Film Physics > The nature of the films
© 2012 www.DissertationTopic.Net  Mobile