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Computational study of the structural phase transitions and pressure dependent electronic structure of ZnOMolepo, Mahlaga Phineas 12 September 2012 (has links)
We use rst-principles calculations based on density functional theory to study the
structural properties and pressure-induced solid-solid phase transitions of ZnO. Both
the local-density approximation (LDA) and the PBE96 form of the generalized gradi-
ent approximation (GGA) are employed together with the projector augmented wave
(PAW) method to mimic the electron-ion interaction. The electronic structure is
investigated by the HSE hybrid functional and a partially self-consistent GWapprox-
imation. We consider the wurtzite (B4), rocksalt (B1), zinc blende (B3), CsCl (B2),
PbO (B10), NaTl (B32), WC (Bh), BN (Bk), NiAs (B81) and AsTi (Bi) modi cations
of ZnO. The calculated structural properties in the B4, B3, B1 and B2 phases compare
acceptably well with those found in previous theoretical studies, as is the transition
pressure between them. We nd that the B4 phase is the most preferred low-pressure
candidate in ZnO while the B2 phase is favorable at high pressures. Apart from the
previously reported B4!B1!B2 phase transition, our study reveals other possible
paths for a transition from B4 to B2 phase with the Bk, Bh, B10, and B81 structures
as intermediate phases. It is found that the HSE and the GW approach o¤er a signif-
icant improvement to the prediction of band-gaps in ZnO. The band-gaps are found
to increase with increasing pressure leading to the structural phase transitions.
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The activity of zinc oxide in multicomponent slagsDavenport, William George January 1960 (has links)
The activity of zinc oxide in multicomponent slags has been investigated. Activities were determined experimentally Toy equilibrating iron saturated brasses with slags containing iron oxide. Required activities in the Zn-Cu-Fe system were obtained from experimental iron saturation data and available information on the Zn-Cu and Cu-Fe systems.
Where measurement was not possible, thermodynamic analyses of slag systems were carried out.
Rigid activity patterns in the ZnO-SiO₂, ZnO-FeO-SiO₂, ZnO-CaO-SiO₂ and ZnO-FeO-CaO-SiO₂ systems have been developed from experimental and analytical data.
Agreement with the activity data of Bell, Turner and Peters on ZnO-FeO-CaO-SiO₂ and Okunev and Bovykin on ZnO-FeO-SiO₂ type slags indicates that the present measurement technique provides a good basis for industrial slag investigations. / Applied Science, Faculty of / Mining Engineering, Keevil Institute of / Graduate
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Activity of ZnO in the ternary system ZnO-CaO-SiO2Fairweather, Michael John January 1967 (has links)
The activity of ZnO in ternary Zno-CaO-SiO₂ slags has been measured at 1300 C by equilibration with copper rich brass and low oxygen potential gas utilizing the following reversible galvanic cell: Pt I H₂,H₂O |0.85Zr0₂-0.15CaO | 0₂(Air)|Pt Thermodynamic data on the component binaries was employed to calculate the excess free energy of the ternary system and the isoactivity patterns of the three components at 1600 C with respect to the metastable pure liquid standard states. An estimate of 6 E.U. was made for the entropy of fusion of ZnO. The measured activities are in good agreement with the calculated values.
The proposed excess free energy contours in the Zno-CaO-SiO₂ ternary are similar in shape to those calculated in a similar manner for the FeO-CaO-SiO₂ system. Also the calculated zinc oxide isoactivity figure resembles
the ferrous oxide isoactivity diagram. This zinc oxide isoactivity pattern projects towards the lime orthosilicate composition. This shape is characteristic of FeO, but in the case of ZnO the projection is less pronounced. Both these observations are in keeping with the slightly more basic behaviour of zinc oxide. / Applied Science, Faculty of / Materials Engineering, Department of / Graduate
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Effect of postdeposition annealing on the electrical and optical properties of ZnOHamad, Omima 01 July 2003 (has links)
No description available.
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Combining zinc oxide and silver for potential optoelectronic applications : a thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Electrical and Computer Engineering at the University of Canterbury, Christchurch, New Zealand /Chai, Jessica H. J. January 1900 (has links)
Thesis (Ph. D.)--University of Canterbury, 2010. / Typescript (photocopy). "February 2010." Includes bibliographical references (p. 168-181). Also available via the World Wide Web.
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Electrochemical Dissolution of ZnO Single CrystalsJustice, David Dixon 01 1900 (has links)
The separation of oxidation-reduction reactions into individual half-cells with a resulting "mixed potential" is well known as a dissolution mechanism for metals; however, the mechanism by which non-conducting crystals lose ions to the solution has been studied only slightly.
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Completeness and sufficiency under normality in mixed model designsVanLeeuwen, Dawn 21 May 1993 (has links)
Graduation date: 1994
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Large-scale patterned oxide nanostructures fabrication, characterization and applications /Wang, Xudong. January 2005 (has links)
Thesis (Ph. D.)--Materials Science and Engineering, Georgia Institute of Technology, 2006. / Wang, Zhong Lin, Committee Chair ; Summers, Christopher J., Committee Co-Chair ; Wong, C. P., Committee Member ; Dupuis, Russell D., Committee Member ; Wagner, Brent, Committee Member
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Fabrication and characterization of zinc oxide (ZnO) nanostructuresLeung, Yu-hang., 梁宇恆. January 2006 (has links)
published_or_final_version / abstract / Physics / Master / Master of Philosophy
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Zinc oxide nanorods and tetrapods: propertiesand applicationsHsu, Yuk-fan., 許玉芬. January 2008 (has links)
published_or_final_version / Physics / Master / Master of Philosophy
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