Journal ArticleDOI
Donor impurity band exchange in dilute ferromagnetic oxides.
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TLDR
It is proposed thatferromagnetic exchange here, and in dilute ferromagnetic nitrides, is mediated by shallow donor electrons that form bound magnetic polarons, which overlap to create a spin-split impurity band.Abstract:
Dilute ferromagnetic oxides having Curie temperatures far in excess of 300 K and exceptionally large ordered moments per transition-metal cation challenge our understanding of magnetism in solids. These materials are high-k dielectrics with degenerate or thermally activated n-type semiconductivity. Conventional super-exchange or double-exchange interactions cannot produce long-range magnetic order at concentrations of magnetic cations of a few percent. We propose that ferromagnetic exchange here, and in dilute ferromagnetic nitrides, is mediated by shallow donor electrons that form bound magnetic polarons, which overlap to create a spin-split impurity band. The Curie temperature in the mean-field approximation varies as (xdelta)(1/2) where x and delta are the concentrations of magnetic cations and donors, respectively. High Curie temperatures arise only when empty minority-spin or majority-spin d states lie at the Fermi level in the impurity band. The magnetic phase diagram includes regions of semiconducting and metallic ferromagnetism, cluster paramagnetism, spin glass and canted antiferromagnetism.read more
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The surface and materials science of tin oxide
Matthias Batzill,Ulrike Diebold +1 more
TL;DR: A review of surface science studies of single crystal surfaces, but selected studies on powder and polycrystalline films are also incorporated in order to provide connecting points between surface sciences studies with the broader field of materials science of tin oxide as discussed by the authors.
Journal ArticleDOI
A ten-year perspective on dilute magnetic semiconductors and oxides
TL;DR: Recent experimental and theoretical developments are reviewed, emphasizing that they not only disentangle many controversies and puzzles accumulated over the past decade but also offer new research prospects.
Journal ArticleDOI
Two‐Dimensional Dielectric Nanosheets: Novel Nanoelectronics From Nanocrystal Building Blocks
Minoru Osada,Takayoshi Sasaki +1 more
TL;DR: The progress made in the properties of dielectric nanosheets is reviewed, highlighting emerging functionalities in electronic applications and a perspective on the advantages offered by this class of materials for future nanoelectronics.
Journal ArticleDOI
First-principles theory of dilute magnetic semiconductors
Kazunori Sato,Lars Bergqvist,Josef Kudrnovský,Peter H. Dederichs,Olle Eriksson,Ilja Turek,Biplab Sanyal,Georges Bouzerar,Hiroshi Katayama-Yoshida,Van An Dinh,Tetsuya Fukushima,Hidetoshi Kizaki,Rudolf Zeller +12 more
TL;DR: In this article, a review summarizes recent first-principles investigations of the electronic structure and magnetism of dilute magnetic semiconductors (DMSs), which are interesting for applications in spintronics.
Journal ArticleDOI
High-precision realization of robust quantum anomalous Hall state in a hard ferromagnetic topological insulator
Cui-Zu Chang,Weiwei Zhao,Duk Y. Kim,Haijun Zhang,Badih A. Assaf,Don Heiman,Shou-Cheng Zhang,Chao-Xing Liu,Moses H. W. Chan,Jagadeesh S. Moodera +9 more
TL;DR: The experimental observation of the QAH state in V-doped (Bi,Sb)2Te3 films with the zero-field longitudinal resistance down to 0.00013 ± 0.00007h/e(2) is reported, a major step towards dissipationless electronic applications in the absence of external fields.
References
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Journal ArticleDOI
Zener Model Description of Ferromagnetism in Zinc-Blende Magnetic Semiconductors
TL;DR: Zener's model of ferromagnetism, originally proposed for transition metals in 1950, can explain T(C) of Ga(1-)(x)Mn(x)As and that of its II-VI counterpart Zn(1)-Mn (x)Te and is used to predict materials with T (C) exceeding room temperature, an important step toward semiconductor electronics that use both charge and spin.
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Room-Temperature Ferromagnetism in Transparent Transition Metal-Doped Titanium Dioxide
Yuji Matsumoto,Makoto Murakami,T. Shono,Tetsuya Hasegawa,Tomoteru Fukumura,Masashi Kawasaki,Parhat Ahmet,Toyohiro Chikyow,Shin-ya Koshihara,Hideomi Koinuma +9 more
TL;DR: The observation of transparent ferromagnetism in cobalt-doped anatase thin films with the concentration of cobalt between 0 and 8% is reported, indicating the existence of ferromagnetic long-range ordering.
Journal ArticleDOI
Magnetic and electric properties of transition-metal-doped ZnO films
TL;DR: In this article, a 3d transition metal-doped ZnO films (n-type Zn1−xMxO) were formed on sapphire substrates using a pulsed-laser deposition technique, and their magnetic and electric properties were examined.