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Article
Electrical and optical properties of single crystalline α-Al2O3 doped with nickel
Nickel, substituting for aluminium in α-Al2O3 acts as an acceptor with a level ∼2.46 eV above the conduction band if a large polaron model applies, ≅ 2.57eV−H(μ h) above the band if a small polaron model applies....
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Article
Creep in polycrystalline Al2O3:Si
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Article
Point Defect Thermodynamics of Compound Semiconductors and their Alloys
The physical properties of crystalline solids depend on the presence of point defects. The concentrations of these defects in turn depend on the conditions of preparation and the presence of dopants. Quantitat...
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Article
Do** behavior of iodine in Hg0.8Cd0.2Te+
Iodine doped single crystal samples of Hg0.8Cd0.2Te were annealed at temperatures varying from 450 to 600°C in Hg vapor and quenched to room temperature. Hall effect measurements at 77 K on the crystals cooled to...
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Article
Pore formation during oxidative annealing of Al2O3 −∶Fe and slowing of grain growth by precipitates and pores
High-density samples of polycrystalline Al2O3 doped with iron retain their high density when annealed at high temperature in a reducing atmosphere, but pores are formed, both inside grains and at grain boundaries...
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Article
Conductivity and creep in acceptor-dominated polycrystalline Al2O3
Ionic and electronic conductivity and compressive creep of hot-pressed polycrystalline acceptor-dominated Al2O3 were measured as a function of oxygen partial pressure and grain size varying from 3 to 200 μm. Hole...
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Chapter
Defect Thermodynamics-Historical
Ionic conduction in crystals was initially attributed to dissociation. In 1926 Frenkel introduced the concept of atomic disorder. Schottky and Wagner (1931-1935) introduced further types of disorder and nonsto...
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Chapter
Electrical Properties of Hexagonal SiC Doped with N, B or Al
In previous papers [1, 2] one of us reported on the preparation of pure and doped single crystals of hexagonal SiC by sublimation in a well defined atmosphere at 2400–2500 °C.
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Chapter
Optical Properties of Pure and Doped SiC
Hexagonal SiC crystals commercially available are usually coloured green or blue in various shades. As has been recognized by various authors, pure hexagonal SiC is a colourless substance with an absorption ed...
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Chapter
The Incorporation of Foreign Atoms in Crystalline solids
The incorporation of foreign atoms in crystals may have a variety of consequences.
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Article
A Relation between Hardness and Stoichiometry in Lead Sulphide Single Crystals
IN the course of an investigation concerning the semiconducting properties of lead sulphide, single crystals were prepared and reheated under various sulphur pressures at 1,200° K. in order to control the devi...
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Chapter
Die Regulierung von elektrischen und optischen Eigenschaften von polaren kristallen
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Article
Tetravalent Manganese as an Activator in Luminescence
THE fluorescence of luminophors activated with manganese, and also of pure manganese compounds, is generally attributed to divalent manganese1. The spectra emitted vary between green and red, and the width of the...
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Article
Fluorescence of Tungstates and Molybdates
THE tungstates of calcium, strontium, magnesium and zinc, and the molybdates of calcium are known to show luminescence upon excitation by cathode rays or short-wave ultra-violet radiation. It is commonly assum...
