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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Electric field effect and transport mechanism research on Co-doped ZnO films

Lin, Cheng-Pang 26 August 2008 (has links)
The mechanism for the room temperature magnetic coupling and electric conduction in oxide diluted magnetic semiconductors (DMS) has been studied simultaneously on the Co:ZnO thin film by utilization of the electric field effect. We find that the carriers are bound on a defect in a radius much larger than the bounded magnetic polaron (BMP) radius, and can move by the variable range hopping (VRH) over a relative small distance. Therefore, a concentric bounded model consisting of a concentric localization configuration with a limited carrier VRH capability was proposed. In this model, the carriers localized around defects couples strongly with the doped magnetic ions forming a BMP in the inner sphere and can only itinerate with no spin coherence in the outer shell. Carriers can hop either by spin-polarized or by spin-independent VRH directly between or not directly between adjacent inner spheres, respectively. This model can explain both the electric and magnetic properties of the oxide DMS, and depicts an evolution of electric and magnetic properties associated with defect concentration.
2

Theory of photo-induced ferro-magnetism in dilute magnetic semiconductors

Mishra, Subodha, January 2006 (has links)
Thesis (Ph. D.) University of Missouri-Columbia, 2006. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file (viewed on August 6, 2007) Includes bibliographical references.
3

Intrinsic vacancy chalcogenides as dilute magnetic semiconductors : theoretical investigation of transition-metal doped gallium selenide /

Gatuna, Ngigi wa. January 2007 (has links)
Thesis (Ph. D.)--University of Washington, 2007. / Includes bibliographical references (leaves 181-186).
4

Study of titanium dioxide based dilute magnetic semiconductors the role of defects and dopants /

Ali, Bakhtyar. January 2008 (has links)
Thesis (M.S.)--University of Delaware, 2008. / Principal faculty advisor: S. Ismat Shah, Dept. of Materials Science. Includes bibliographical references.
5

Optical spectroscopy of Cd←1←←←xMn←xTe heterostructures

Railson, Stuart Vaughan January 1996 (has links)
No description available.
6

Synthesis and study of ZnO nanostructures and ZnO based quasi-1d dilute magnetic semiconductors. / 氧化鋅的納米結構以及准一維氧化鋅稀磁半導體的合成及研究 / Synthesis and study of ZnO nanostructures and ZnO based quasi-1d dilute magnetic semiconductors. / Yang hua xin de na mi jie gou yi ji zhun yi wei yang hua xin xi ci ban dao ti de he cheng ji yan jiu

January 2008 (has links)
Rao, Yangyan = 氧化鋅的納米結構以及准一維氧化鋅稀磁半導體的合成及研究 / 饒洋燕. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2008. / Includes bibliographical references. / Abstracts in English and Chinese. / Rao, Yangyan = Yang hua xin de na mi jie gou yi ji zhun yi wei yang hua xin xi ci ban dao ti de he cheng ji yan jiu / Rao Yangyan. / Abstract --- p.1 / 摘要 --- p.3 / Acknowledgments --- p.4 / Table of contents --- p.5 / Chapter Chapter 1 --- Introduction --- p.7 / Chapter 1.1 --- Zinc oxide --- p.7 / Chapter 1.2 --- Mn doped ZnO diluted magnetic semiconductors --- p.7 / Chapter 1.3 --- Motivations --- p.9 / Chapter 1.4 --- Our Work --- p.10 / Chapter 1.5 --- Overview of the thesis --- p.11 / References --- p.11 / Chapter Chapter 2 --- Experimental set-up and conditions --- p.15 / Chapter 2.1 --- Chemical Vapor Deposition --- p.15 / Chapter 2.1.1 --- Key Steps in Chemical Vapor Deposition --- p.15 / Chapter 2.2 --- Experiments on the synthesis of ZnO nanostructures --- p.16 / Chapter 2.2.1 --- Set-up --- p.17 / Chapter 2.2.2 --- Growth mechanism --- p.18 / Chapter 2.2.3 --- Experimental conditions --- p.20 / References --- p.23 / Chapter Chapter 3 --- Characterization of pure ZnO --- p.25 / Chapter 3.1 --- Morphology of ZnO nanowires --- p.25 / Chapter 3.2 --- Lattice structure --- p.30 / Chapter 3.3 --- Photoluminescence property (PL) --- p.32 / Chapter 3.4 --- Lattice dynamics´ؤRaman spectra --- p.33 / References --- p.35 / Chapter Chapter 4 --- Properties of Mn doped ZnO nanowires --- p.37 / Chapter 4.1 --- Morphology and composition --- p.37 / Chapter 4.2 --- Lattice structure of Mn-doped ZnO --- p.40 / Chapter 4.3 --- Lattice dynamics´ؤRaman study of Mn-doped ZnO nanowires --- p.46 / References --- p.48 / Chapter Chapter 5 --- Magnetic properties of Mn doped ZnO nanowires --- p.50 / Chapter 5.1 --- Theory of DMS --- p.50 / Chapter 5.2 --- Magnetic results of Mn doped ZnO nanowires --- p.52 / Chapter 5.2.1 --- Paramagnetism of Mn doped ZnO --- p.52 / Chapter 5.2.2 --- Ferromagnetism of Mn doped ZnO --- p.58 / References --- p.65 / Chapter Chapter 6 --- Conclusions --- p.67
7

Magnetic nanocrystals : synthesis and properties of diluted magnetic semiconductor quantum dots /

Norberg, Nicholas S. January 2006 (has links)
Thesis (Ph. D.)--University of Washington, 2006. / Vita. Includes bibliographical references (leaves 163-175).
8

Spin-dependent transport in magnetic tunnel junctions and diluted magnetic semiconductors

Wang, Weigang. January 2009 (has links)
Thesis (Ph.D.)--University of Delaware, 2008. / Principal faculty advisor: John Q. Xiao, Dept. of Physics and Astronomy. Includes bibliographical references.
9

Chemical synthesis and characterization of CdMnS and CdMnSe quantum dots /

Guo, Bicheng. January 2004 (has links)
Thesis (M. Phil.)--Hong Kong University of Science and Technology, 2004. / Includes bibliographical references (leaves 63-66). Also available in electronic version. Access restricted to campus users.
10

Synthesis, spectroscopy, and magnetism of diluted magnetic semiconductor nanocrystals /

Radovanovic, Pavle V. January 2004 (has links)
Thesis (Ph. D.)--University of Washington, 2004. / Vita. Includes bibliographical references (leaves 155-170).

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