{"id":{"repo_id":"birmingham","oai_identifier":"oai:etheses.bham.ac.uk:1512"},"canonical_url":"https://search.dev.ndltd.org/etd/birmingham/oai:etheses.bham.ac.uk:1512","repository":{"repo_id":"birmingham","name":"University of Birmingham","base_url":"https://etheses.bham.ac.uk/cgi/oai2"},"display":{"title":"Structural and magnetic characterisation of some mixed metal oxides and oxyhalides","abstract":"This thesis investigates the structural and physical effects of changing the ratio of Mn:Ga in the anion deficient perovskite, YSr\\(_3\\)Mn\\(_{4-x}\\)GaxO\\(_{10.5}\\). YSr\\(_3\\)Mn\\(_{4-x}\\)GaxO\\(_{10.5}\\) crystallises in the tetragonal space group I4/mmm, with lattice parameters a~7.64 Å and c~15.66 Å. Magnetic characterisation indicates that the material is antiferromagnetic overall, with ferromagnetic ordering in the [001] direction of the unit cell. Earlier work on the structural analogue, Y\\(_{1.07}\\)Sr\\(_{2.93}\\)Mn\\(_{2.67}\\)Ga\\(_{1.33}\\)O\\(_{10.5}\\), identified a magnetic peak in the neutron diffraction pattern that could not be fitted following refinement of NPD data. This work concluded that the extra peak was due to a small MnO impurity. The effects of oxidation and fluorination on the structural and physical properties of YSr\\(_3\\)Mn\\(_{4-x}\\)Ga\\(_x\\)O\\(_{10.5}\\) with various Mn:Ga ratios are investigated. The physical and structural effects of substituting Mn\\(^{3+}\\) or Co\\(^{3+}\\) for Fe\\(^{3+}\\) in the perovskite related material, Pb\\(_4\\)Fe\\(_3\\)O\\(_8\\)Cl, have been investigated using XRPD, NPD and magnetic susceptibility measurements. An earlier characterisation of Pb\\(_8\\)WO\\(_{10}\\)Cl\\(_2\\) suggested a deficit on all atom sites within the unit cell. This work suggests a different structure with an intact cation and main oxygen sub-lattice. The site of an additional oxygen was established linked to tungsten. Pb\\(_8\\)WO\\(_{10}\\)Cl\\(_2\\) crystallises in space group I4/mmm, with a = 3.9846(2) and c = 22.690(2) Å.","abstract_html":"This thesis investigates the structural and physical effects of changing the ratio of Mn:Ga in the anion deficient perovskite, YSr<span class=\"etd-inline-math\"><sub>3</sub></span>Mn<span class=\"etd-inline-math\"><sub>4-x</sub></span>GaxO<span class=\"etd-inline-math\"><sub>10.5</sub></span>. YSr<span class=\"etd-inline-math\"><sub>3</sub></span>Mn<span class=\"etd-inline-math\"><sub>4-x</sub></span>GaxO<span class=\"etd-inline-math\"><sub>10.5</sub></span> crystallises in the tetragonal space group I4/mmm, with lattice parameters a~7.64 Å and c~15.66 Å. Magnetic characterisation indicates that the material is antiferromagnetic overall, with ferromagnetic ordering in the [001] direction of the unit cell. Earlier work on the structural analogue, Y<span class=\"etd-inline-math\"><sub>1.07</sub></span>Sr<span class=\"etd-inline-math\"><sub>2.93</sub></span>Mn<span class=\"etd-inline-math\"><sub>2.67</sub></span>Ga<span class=\"etd-inline-math\"><sub>1.33</sub></span>O<span class=\"etd-inline-math\"><sub>10.5</sub></span>, identified a magnetic peak in the neutron diffraction pattern that could not be fitted following refinement of NPD data. This work concluded that the extra peak was due to a small MnO impurity. The effects of oxidation and fluorination on the structural and physical properties of YSr<span class=\"etd-inline-math\"><sub>3</sub></span>Mn<span class=\"etd-inline-math\"><sub>4-x</sub></span>Ga<span class=\"etd-inline-math\"><sub>x</sub></span>O<span class=\"etd-inline-math\"><sub>10.5</sub></span> with various Mn:Ga ratios are investigated. The physical and structural effects of substituting Mn<span class=\"etd-inline-math\"><sup>3+</sup></span> or Co<span class=\"etd-inline-math\"><sup>3+</sup></span> for Fe<span class=\"etd-inline-math\"><sup>3+</sup></span> in the perovskite related material, Pb<span class=\"etd-inline-math\"><sub>4</sub></span>Fe<span class=\"etd-inline-math\"><sub>3</sub></span>O<span class=\"etd-inline-math\"><sub>8</sub></span>Cl, have been investigated using XRPD, NPD and magnetic susceptibility measurements. An earlier characterisation of Pb<span class=\"etd-inline-math\"><sub>8</sub></span>WO<span class=\"etd-inline-math\"><sub>10</sub></span>Cl<span class=\"etd-inline-math\"><sub>2</sub></span> suggested a deficit on all atom sites within the unit cell. This work suggests a different structure with an intact cation and main oxygen sub-lattice. The site of an additional oxygen was established linked to tungsten. Pb<span class=\"etd-inline-math\"><sub>8</sub></span>WO<span class=\"etd-inline-math\"><sub>10</sub></span>Cl<span class=\"etd-inline-math\"><sub>2</sub></span> crystallises in space group I4/mmm, with a = 3.9846(2) and c = 22.690(2) Å.","abstract_has_math":true,"creators":["Stephens, Deborah Ann"],"institution":"University of Birmingham","degree_name":"d_ph","degree_level":"d_ph","degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-07","date_published":"2011-07","updated_at":"2026-07-24T01:11:33Z","subjects":["TP Chemical technology","QD Chemistry"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":null,"outbound_label":null,"outbound_source":null},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.sponsor","label":"Sponsor","values":["na"]},{"key":"dc:creator","label":"Author","values":["Stephens, Deborah Ann"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-07"]},{"key":"dc:date.issued","label":"Date","values":["2011-07"]},{"key":"dc:publisher.department","label":"Dc Publisher Department","values":["College of Engineering & Physical Sciences","School of Chemistry"]},{"key":"dc:publisher.institution","label":"Dc Publisher Institution","values":["University of Birmingham"]},{"key":"dc:relation.isreferencedby","label":"Dc Relation Isreferencedby","values":["http://etheses.bham.ac.uk//id/eprint/1512/"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"dc:type.qualificationlevel","label":"Dc Type Qualificationlevel","values":["d_ph"]},{"key":"dc:type.qualificationname","label":"Dc Type Qualificationname","values":["d_ph"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["TP Chemical technology","QD Chemistry"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://etheses.bham.ac.uk//id/eprint/1512/1/Stephens11PhD.pdf","http://etheses.bham.ac.uk//id/eprint/1512/2/Decl_IS_Stephens11PhD.pdf"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["This thesis investigates the structural and physical effects of changing the ratio of Mn:Ga in the anion deficient perovskite, YSr\\(_3\\)Mn\\(_{4-x}\\)GaxO\\(_{10.5}\\). YSr\\(_3\\)Mn\\(_{4-x}\\)GaxO\\(_{10.5}\\) crystallises in the tetragonal space group I4/mmm, with lattice parameters a~7.64 Å and c~15.66 Å. Magnetic characterisation indicates that the material is antiferromagnetic overall, with ferromagnetic ordering in the [001] direction of the unit cell. Earlier work on the structural analogue, Y\\(_{1.07}\\)Sr\\(_{2.93}\\)Mn\\(_{2.67}\\)Ga\\(_{1.33}\\)O\\(_{10.5}\\), identified a magnetic peak in the neutron diffraction pattern that could not be fitted following refinement of NPD data. This work concluded that the extra peak was due to a small MnO impurity. The effects of oxidation and fluorination on the structural and physical properties of YSr\\(_3\\)Mn\\(_{4-x}\\)Ga\\(_x\\)O\\(_{10.5}\\) with various Mn:Ga ratios are investigated. The physical and structural effects of substituting Mn\\(^{3+}\\) or Co\\(^{3+}\\) for Fe\\(^{3+}\\) in the perovskite related material, Pb\\(_4\\)Fe\\(_3\\)O\\(_8\\)Cl, have been investigated using XRPD, NPD and magnetic susceptibility measurements. An earlier characterisation of Pb\\(_8\\)WO\\(_{10}\\)Cl\\(_2\\) suggested a deficit on all atom sites within the unit cell. This work suggests a different structure with an intact cation and main oxygen sub-lattice. The site of an additional oxygen was established linked to tungsten. Pb\\(_8\\)WO\\(_{10}\\)Cl\\(_2\\) crystallises in space group I4/mmm, with a = 3.9846(2) and c = 22.690(2) Å."]},{"key":"dc:format","label":"Dc Format","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Structural and magnetic characterisation of some mixed metal oxides and oxyhalides"]}]}],"canonical_facts":{"dc:contributor.sponsor":["na"],"dc:creator":["Stephens, Deborah Ann"],"dc:date":["2011-07"],"dc:date.issued":["2011-07"],"dc:description.abstract":["This thesis investigates the structural and physical effects of changing the ratio of Mn:Ga in the anion deficient perovskite, YSr\\(_3\\)Mn\\(_{4-x}\\)GaxO\\(_{10.5}\\). YSr\\(_3\\)Mn\\(_{4-x}\\)GaxO\\(_{10.5}\\) crystallises in the tetragonal space group I4/mmm, with lattice parameters a~7.64 Å and c~15.66 Å. Magnetic characterisation indicates that the material is antiferromagnetic overall, with ferromagnetic ordering in the [001] direction of the unit cell. Earlier work on the structural analogue, Y\\(_{1.07}\\)Sr\\(_{2.93}\\)Mn\\(_{2.67}\\)Ga\\(_{1.33}\\)O\\(_{10.5}\\), identified a magnetic peak in the neutron diffraction pattern that could not be fitted following refinement of NPD data. This work concluded that the extra peak was due to a small MnO impurity. The effects of oxidation and fluorination on the structural and physical properties of YSr\\(_3\\)Mn\\(_{4-x}\\)Ga\\(_x\\)O\\(_{10.5}\\) with various Mn:Ga ratios are investigated. The physical and structural effects of substituting Mn\\(^{3+}\\) or Co\\(^{3+}\\) for Fe\\(^{3+}\\) in the perovskite related material, Pb\\(_4\\)Fe\\(_3\\)O\\(_8\\)Cl, have been investigated using XRPD, NPD and magnetic susceptibility measurements. An earlier characterisation of Pb\\(_8\\)WO\\(_{10}\\)Cl\\(_2\\) suggested a deficit on all atom sites within the unit cell. This work suggests a different structure with an intact cation and main oxygen sub-lattice. The site of an additional oxygen was established linked to tungsten. Pb\\(_8\\)WO\\(_{10}\\)Cl\\(_2\\) crystallises in space group I4/mmm, with a = 3.9846(2) and c = 22.690(2) Å."],"dc:format":["application/pdf"],"dc:identifier.uri":["http://etheses.bham.ac.uk//id/eprint/1512/1/Stephens11PhD.pdf","http://etheses.bham.ac.uk//id/eprint/1512/2/Decl_IS_Stephens11PhD.pdf"],"dc:publisher.department":["College of Engineering & Physical Sciences","School of Chemistry"],"dc:publisher.institution":["University of Birmingham"],"dc:relation.isreferencedby":["http://etheses.bham.ac.uk//id/eprint/1512/"],"dc:subject":["TP Chemical technology","QD Chemistry"],"dc:title":["Structural and magnetic characterisation of some mixed metal oxides and oxyhalides"],"dc:type":["Thesis"],"dc:type.qualificationlevel":["d_ph"],"dc:type.qualificationname":["d_ph"]},"updated_at":"2026-07-24T01:11:33Z"}