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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.
61

Structural properties of multi-layered materials

Loader, Charlotte Bree January 2000 (has links)
No description available.
62

Properties of magnetostrictive alloys at elevated temperatures

Prajapati, Kamlesh January 1995 (has links)
No description available.
63

The synthesis, structure and reactivity of iron-bismuth complexes : Potential Molecular Precursors for Multiferroic BiFeO3

Wójcik, Katarzyna 15 June 2010 (has links) (PDF)
The thesis presented here is focused on the synthesis of iron-bismuth alkoxides and siloxides as precursors for multiferroic BiFeO<sub>3</sub> systems. Spectrum of novel cyclopentadienyl substituted iron-bismuth complexes of the general type [{Cp<sup>y</sup>(CO)<sub>2</sub>Fe}BiX<sub>2</sub>], as potential precursors for cyclopentadienyl iron-bismuth alkoxides or siloxides [{Cp<sup>y</sup>(CO)<sub>2</sub>Fe}Bi(OR)<sub>2</sub>] (R-O<sup>t</sup>Bu, OSiMe<sub>2</sub><sup>t</sup>Bu), were obtained and characterised. The use of wide range of cyclopentadienyl rings in the iron carbonyl compounds allowed for a comprehensive analysis of its influence on structure, reactivity as well as solubility of the studied complexes, which are crucial features of potential precursors. The results fill the gap in the chemistry of cyclopentadienyl iron-bismuth complexes. In this work a new method of preparation of novel alkoxides or siloxides iron-bismuth complexes has been developed. In the reaction of Fe<sub>2</sub>(CO)<sub>9</sub> with Bi(O<sup>t</sup>Bu)<sub>3</sub> or Bi(OSiMe<sub>2</sub><sup>t</sup>Bu)<sub>3</sub> molecular precursors for preparation of heterobimetallic oxides were obtained. Moreover, characterised compounds allowed to extend the knowledge about existence of iron-bismuth clusters and open new ways for the further investigations on the carbonyl iron-bismuth siloxides and alkoxides. The resulting compounds are good single source precursors for the BiFeO<sub>3</sub> materials. The presented synthetic route can be generalized and other heterobimetallic compounds can be obtained. This work should also be helpful in the designing new precursors for synthesis of metal oxides.
64

The synthesis, structure and reactivity of iron-bismuth complexes : Potential Molecular Precursors for Multiferroic BiFeO3

Wójcik, Katarzyna 30 March 2010 (has links)
The thesis presented here is focused on the synthesis of iron-bismuth alkoxides and siloxides as precursors for multiferroic BiFeO<sub>3</sub> systems. Spectrum of novel cyclopentadienyl substituted iron-bismuth complexes of the general type [{Cp<sup>y</sup>(CO)<sub>2</sub>Fe}BiX<sub>2</sub>], as potential precursors for cyclopentadienyl iron-bismuth alkoxides or siloxides [{Cp<sup>y</sup>(CO)<sub>2</sub>Fe}Bi(OR)<sub>2</sub>] (R-O<sup>t</sup>Bu, OSiMe<sub>2</sub><sup>t</sup>Bu), were obtained and characterised. The use of wide range of cyclopentadienyl rings in the iron carbonyl compounds allowed for a comprehensive analysis of its influence on structure, reactivity as well as solubility of the studied complexes, which are crucial features of potential precursors. The results fill the gap in the chemistry of cyclopentadienyl iron-bismuth complexes. In this work a new method of preparation of novel alkoxides or siloxides iron-bismuth complexes has been developed. In the reaction of Fe<sub>2</sub>(CO)<sub>9</sub> with Bi(O<sup>t</sup>Bu)<sub>3</sub> or Bi(OSiMe<sub>2</sub><sup>t</sup>Bu)<sub>3</sub> molecular precursors for preparation of heterobimetallic oxides were obtained. Moreover, characterised compounds allowed to extend the knowledge about existence of iron-bismuth clusters and open new ways for the further investigations on the carbonyl iron-bismuth siloxides and alkoxides. The resulting compounds are good single source precursors for the BiFeO<sub>3</sub> materials. The presented synthetic route can be generalized and other heterobimetallic compounds can be obtained. This work should also be helpful in the designing new precursors for synthesis of metal oxides.
65

Synthesis of lithium manganese phosphate by controlled sol-gel method and design of all solid state lithium ion batteries

Penumaka, Rani Vijaya January 2015 (has links)
Indiana University-Purdue University Indianapolis (IUPUI) / Due to the drastic increase in the cost of fossil fuels and other environmental issues, the demand for energy and its storage has risen globally. Rather than being dependent on intermittent energy sources like wind and solar energy, focus has been on alternative energy sources. To eliminate the need for fossil fuels, advances are being made to provide energy for hybrid electric vehicles (HEV), plug-in hybrid vehicles (PHEV) and pure electric vehicles (EV) thus providing scope for much greener environment. Hence, focus has been on development in lithium ion batteries to provide with materials that have high energy density and voltage. Ortho olivine lithium transitional metals are known to be abundant and inexpensive; these compounds are less noxious than other cathode materials. Advancement in research is being done in finding iron and manganese compounds as cathode materials for advanced technologies. However, Lithium manganese phosphates are known to suffer with poor electrochemical performances due the manganese dissolution in the organic liquid electrolyte due to Jahn-Teller Lattice distortion. This problem was tried to endorse in this thesis. In the second chapter by synthesizing nano sized cathode particles with good electronic conductivity, good performance was achieved. In the third chapter additive olivine cathode was synthesized my modified sol gel process. A wt. % of TMSP was added as an additive in the organic liquid electrolyte. By comparing the properties between the two kinds of electrolytes it was observed that by the addition of the additive in the organic electrolyte good electrochemical properties could be achieved hindering the Mn dissolution in the electrolyte. In the final chapter, a composite solid electrolyte was fabricated by using NASICON-type glass ceramic of Lithium aluminum titanium phosphate (LATP) with organic binder of Polyethylene oxide. The flexible solid electrolyte exhibited good ionic conductivity. An all solid state cell was fabricated using the composite solid electrolyte using LiMn2O4 as the symmetric electrodes. At different pressures, the performance of the solid state cell was studied.

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