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dc.contributor.advisorSahoo, Balaram
dc.contributor.authorNarayan, Laxmi
dc.date.accessioned2021-02-19T05:45:57Z
dc.date.available2021-02-19T05:45:57Z
dc.date.submitted2018
dc.identifier.urihttps://etd.iisc.ac.in/handle/2005/4882
dc.description.abstractThe structural and magnetic properties of Al substituted yttrium-iron garnet (Y3AlxFe5-xO12, x = 0, 0.1, 0.2, 0.3, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, 1.6 and 1.8) ceramic powders synthesized using solution combustion method were investigated. For low Al content, Al3+ ions have preference to occupy tetrahedral (Td) sites than the octahedral (Oh) sites. At higher Al content the distribution of Al tends towards a ratio of 3:2 at the tetrahedral:octahedral site. Increase in Al doping results in the decrease in the lattice parameter due to smaller size of Al3+ as compared to Fe3+ ion. All the studied samples show coral-network-like surface morphology. The saturation magnetization (MS) values decrease from ∼26.94 emu/g to ∼ 0.17 emu/g with increase in Al content from 0.0 to 1.8. Further addition of Al makes the sample paramagnetic at RT. Substitution of non-magnetic Al3+ reduces the saturation magnetization rapidly due to the decrease in the superexchange interaction in the crystal. Furthermore, solution combustion synthesis of Mn, Sr or Fe-doped zinc oxide ceramic samples was carried out. All the samples were characterized by XRD, SEM and UV-DRS. The magnetic order of Fe in ZnO lattice of the Fe-doped ZnO samples was characterized by Mössbauer spectroscopy. The X-ray diffractograms determine the solubility limits of dopant in the host (ZnO) lattice. Electron micrographs confirmed the spongy network nanostructure of all the samples. The bandgap of the samples was estimated from Tauc plots of corresponding UV-DRS spectra. The spongy (high surface area) and low bandgap of Fe-ZnO renders it as an important candidate for photocatalytic applications. Our results show that among all these samples, Fe-doped zinc oxide nanoparticles can be the most suitable candidate for photocatalytic applications.en_US
dc.language.isoen_USen_US
dc.relation.ispartofseries;G29744
dc.rightsI grant Indian Institute of Science the right to archive and to make available my thesis or dissertation in whole or in part in all forms of media, now hereafter known. I retain all proprietary rights, such as patent rights. I also retain the right to use in future works (such as articles or books) all or part of this thesis or dissertationen_US
dc.subjectyttrium-iron garneten_US
dc.subjectFe-doped zinc oxide nanoparticlesen_US
dc.subjectphotocatalytic applicationsen_US
dc.subject.classificationResearch Subject Categories::NATURAL SCIENCES::Chemistry::Other chemistryen_US
dc.titleStructural and magnetic properties of Al-doped yttrium iron aluminum garnet and optical properties of Mn, Sr, Fe-doped ZnO prepared by solution combustion methoden_US
dc.typeThesisen_US
dc.degree.nameMSen_US
dc.degree.levelMastersen_US
dc.degree.grantorIndian Institute of Scienceen_US
dc.degree.disciplineFaculty of Scienceen_US


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