CHARACTERISTICS OF ELECTRICAL AND MAGNETIC PROPERTIES OF MATERIALS STRONTIUM COBALTITE
SrCoO3-? is a material that can have an oxygen amount of 2.5-3. If the oxygen deficiency is (?=0,5) then oxygen vacancy will occur and form SrCoO2,5 called the brownmillerite phase which has an orthorhombic structure. Howefer, if the pxygen deficiency value is (?=0) it will form a perfect perovskite...
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| Format: | Theses |
| Language: | Indonesia |
| Online Access: | https://digilib.itb.ac.id/gdl/view/63305 |
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| Institution: | Institut Teknologi Bandung |
| Language: | Indonesia |
| Summary: | SrCoO3-? is a material that can have an oxygen amount of 2.5-3. If the oxygen deficiency is (?=0,5) then oxygen vacancy will occur and form SrCoO2,5 called the brownmillerite phase which has an orthorhombic structure. Howefer, if the pxygen deficiency value is (?=0) it will form a perfect perovskite SrCoO3 phase which has a cubic structure. In this research the sol-gel method was use then the quenching process was carried out using H2O to get the brownmillerite phase. By using this method SrCoO2,5 with single phase was synthesized. To obtain the SrCoO3 phase, an oxidation process was carried out using KMnO4. However, chemical oxidation causes the formation of secondary phase CoO as a result of the reaction of the material with the oxidation medium. In addition oxidation with KMnO4 will remaining K and Mn atoms from the result of measurement Energy-dispersive X-ray spectroscopy. A more precise amount of oxygen content is determined by iodometric titration and the result is O?2,5; O=2,77. The SrCoO2,5 phase has semiconductor properties which the energy gap Eg=0,09eV. Meanwhile the Seebeck coefficient is negative with the largest value at a temperature 330K (S=-460,79?V/K). SrCoO2,77 phase has a higher magnetization value than SrCoO2,5. This is because the cobalt ion in SrCoO2,77 interacts ferromagnetically. |
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