2 research outputs found

    Synthesis, structural and magnetic properties of Ca1-xGdxMnO3 nanopowders

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    Π£ ΠΎΠΊΠ²ΠΈΡ€Ρƒ ΠΎΠ²Π΅ докторскС Ρ‚Π΅Π·Π΅, испитиванС су ΠΎΠΏΡ‚ΠΈΠΌΠ°Π»Π½Π΅ ΠΌΠ΅Ρ‚ΠΎΠ΄Π΅ Π·Π° Π΄ΠΎΠ±ΠΈΡ˜Π°ΡšΠ΅Π½Π°Π½ΠΎΠΏΡ€Π°Ρ…Π° – ΠΊΠ°Π»Ρ†ΠΈΡ˜ΡƒΠΌ манганског оксида Π΄ΠΎΠΏΠΈΡ€Π°Π½ΠΎΠ³ јонима Π³Π°Π΄ΠΎΠ»ΠΈΠ½ΠΈΡ˜ΡƒΠΌΠ°. Π¦ΠΈΡ™ΠΈΡΡ‚Ρ€Π°ΠΆΠΈΠ²Π°ΡšΠ° јС ΠΈΡΠΏΠΈΡ‚ΠΈΠ²Π°ΡšΠ΅ ΠΎΠ΄Π³ΠΎΠ²Π°Ρ€Π°Ρ˜ΡƒΡ›ΠΈΡ… прСкурсора који су подСсни Π΄Π° ΡΠ΅Π΄ΠΎΠ±ΠΈΡ˜Ρƒ чисти Π½Π°Π½ΠΎ ΠΏΡ€Π°Ρ…ΠΎΠ²ΠΈ ΠΌΠ°Π½Π³Π°Π½ΠΈΡ‚Π° са пСровскитском структуром, ΠΊΠ°ΠΎ ΠΈΠΌΠΎΠ½ΠΎΡ„Π°Π·Π½ΠΈ чврсти раствори са пСровскитском структуром. Као подСсан ΠΌΠ΅Ρ‚ΠΎΠ΄ΠΊΠΎΡ€ΠΈΡˆΡ›Π΅Π½Π° јС ΠΌΠΎΠ΄ΠΈΡ„ΠΈΠΊΠΎΠ²Π°Π½Π° Π³Π»ΠΈΡ†ΠΈΠ½ Π½ΠΈΡ‚Ρ€Π°Ρ‚Π½Π° ΠΌΠ΅Ρ‚ΠΎΠ΄Π°, Π° ΠΎΠ΄ прСкурсора Π½ΠΈΡ‚Ρ€Π°Ρ‚ΠΈ ΠΈΠ°Ρ†Π΅Ρ‚Π°Ρ‚ΠΈ ΠΎΠ΄Π³ΠΎΠ²Π°Ρ€Π°Ρ˜ΡƒΡ›ΠΈΡ… ΠΌΠ΅Ρ‚Π°Π»Π°. ΠœΠΎΠ΄ΠΈΡ„ΠΈΠΊΠ°Ρ†ΠΈΡ˜Π° Π³Π»ΠΈΡ†ΠΈΠ½ Π½ΠΈΡ‚Ρ€Π°Ρ‚Π½Π΅ ΠΌΠ΅Ρ‚ΠΎΠ΄Π΅ сС односина Π΄Π΅Π»ΠΈΠΌΠΈΡ‡Π½Ρƒ Π·Π°ΠΌΠ΅Π½Ρƒ Π½ΠΈΡ‚Ρ€Π°Ρ‚Π° Π°Ρ†Π΅Ρ‚Π°Ρ‚ΠΈΠΌΠ°, Ρ‡ΠΈΠΌΠ΅ јС ΡƒΠ±Π»Π°ΠΆΠ΅Π½Π° бурност Ρ€Π΅Π°ΠΊΡ†ΠΈΡ˜Π΅.Π˜ΡΠΏΠΈΡ‚Π°Π½ јС Ρ€Π°Π·Π»ΠΈΡ‡ΠΈΡ‚ΠΈ однос прСкурсора, који Π΄Π°Ρ˜Ρƒ наночСстичнС ΠΏΡ€Π°Ρ…ΠΎΠ²Π΅ ΠΈ ΠΈΠΌΠ°Ρ˜ΡƒΠΌΠ°Π»ΠΈ Π³ΡƒΠ±ΠΈΡ‚Π°ΠΊ ΠΏΡ€ΠΈ Ρ€Π΅Π°ΠΊΡ†ΠΈΡ˜Π°ΠΌΠ°. БинтСтисано јС ΡƒΠΊΡƒΠΏΠ½ΠΎ Ρ‡Π΅Ρ‚ΠΈΡ€ΠΈ Π½Π°Π½ΠΎΠΏΡ€Π°Ρ…Π° ΠΏΡ€ΠΈΠΌΠ΅Π½ΠΎΠΌΠΌΠΎΠ΄ΠΈΡ„ΠΈΠΊΠΎΠ²Π°Π½Π΅ Π³Π»ΠΈΡ†ΠΈΠ½ Π½ΠΈΡ‚Ρ€Π°Ρ‚Π½Π΅ ΠΌΠ΅Ρ‚ΠΎΠ΄Π΅ са слСдСћим Π½ΠΎΠΌΠΈΠ½Π°Π»Π½ΠΈΠΌ саставом:Ca0,95Gd0,05MnO3; Ca0,9Gd0,1MnO3; Ca0,85Gd0,15MnO3; Ca0,8Gd0,2MnO3. Π”ΠΎΠ±ΠΈΡ˜Π΅Π½ΠΈΠΏΡ€Π°Ρ…ΠΎΠ²ΠΈ су Π΄Π°Ρ™Π΅ калцинисани Ρƒ Ρ‚Π΅ΠΌΠΏΠ΅Ρ€Π°Ρ‚ΡƒΡ€Π½ΠΎΠΌ ΠΈΠ½Ρ‚Π΅Ρ€Π²Π°Π»Ρƒ ΠΎΠ΄ 850 ΠΎΠ‘ Π΄ΠΎ 950 ΠΎΠ‘ 10min. Π’Π΅ΠΌΠΏΠ΅Ρ€Π°Ρ‚ΡƒΡ€Π½ΠΈ опсСг Ρƒ ΠΊΠΎΠΌΠ΅ су посматрани калцинисани ΡƒΠ·ΠΎΡ€Ρ†ΠΈ, добијСн Ρ˜Π΅ΠΊΠΎΡ€ΠΈΡˆΡ›Π΅ΡšΠ΅ΠΌ Π΄ΠΈΡ„Π΅Ρ€Π΅Π½Ρ†ΠΈΡ˜Π°Π»Π½ΠΎ Ρ‚Π΅Ρ€ΠΌΠΈΡ˜ΡΠΊΠ΅ Π°Π½Π°Π»ΠΈΠ·Π΅ (ДВА). ЕкспСримСнтално суодрСђСнС ΠΎΠΏΡ‚ΠΈΠΌΠ°Π»Π½Π΅ Ρ‚Π΅ΠΌΠΏΠ΅Ρ€Π°Ρ‚ΡƒΡ€Π΅ ΡΠΈΠ½Ρ‚Π΅Ρ€ΠΎΠ²Π°ΡšΠ° ΠΈ Π½Π°Π»Π°Π·Π΅ сС Ρƒ опсСгу ΠΎΠ΄ 1350 Π΄ΠΎ1450 ΠΎΠ‘.ΠœΠ΅Ρ‚ΠΎΠ΄ΠΎΠΌ рСндгСнскС Π΄ΠΈΡ„Ρ€Π°ΠΊΡ†ΠΈΠΎΠ½Π΅ Π°Π½Π°Π»ΠΈΠ·Π΅ ΠΈ Π ΠΈΡ‚Π²Π΅Π»Π΄ΠΎΠ²ΠΎΠ³ ΡΡ‚Ρ€ΡƒΠΊΡ‚ΡƒΡ€Π½ΠΎΠ³ΡƒΡ‚Π°Ρ‡ΡšΠ°Π²Π°ΡšΠ° ΠΈΠ·Π²Ρ€ΡˆΠ΅Π½Π° јС структурна ΠΈ микроструктурна ΠΊΠ°Ρ€Π°ΠΊΡ‚Π΅Ρ€ΠΈΠ·Π°Ρ†ΠΈΡ˜Π°Π‘Π°1-xGdxMnO3 (Ρ… = 0,05; 0,1; 0,15; 0,2) Π½Π°Π½ΠΎΠΏΡ€Π°Ρ…ΠΎΠ²Π°. На Ρ‚Π°Ρ˜ Π½Π°Ρ‡ΠΈΠ½ јС ΡƒΡ‚Π²Ρ€Ρ’Π΅Π½ΠΌΠΎΠ½ΠΎΡ„Π°Π·Π°Π½ састав свих ΡƒΠ·ΠΎΡ€Π°ΠΊΠ°, просторна Π³Ρ€ΡƒΠΏΠ° Pnma Π°Π»ΠΈ ΠΈ Ρ‚ΠΎ, Π΄Π° су овипСровскити ΡƒΠ³Ρ€Π°Π΄ΡšΠΎΠΌ Gd3+ дСформисани. Анализом ΠΏΠ°Ρ€Π°ΠΌΠ΅Ρ‚Π°Ρ€Π° Ρ˜Π΅Π΄ΠΈΠ½ΠΈΡ‡Π½Π΅ Ρ›Π΅Π»ΠΈΡ˜Π΅ΡƒΡΡ‚Π°Π½ΠΎΠ²Ρ™Π΅Π½ΠΎ јС Π΄Π° ΠΏΠΎΠ²Π΅Ρ›Π°ΡšΠ΅ ΠΏΠ°Ρ€Π°ΠΌΠ΅Ρ‚Π°Ρ€Π° ΠΈ ΠΏΡ€ΠΎΠΌΠ΅Π½Π° Ρƒ просСчним Π΄ΡƒΠΆΠΈΠ½Π°ΠΌΠ° Mnβ”€ΠžΠ²Π΅Π·Π° Π½Π°ΡΡ‚Π°Ρ˜Π΅ услСд ΠΏΠΎΠ²Π΅Ρ›Π°ΡšΠ° ΡΠ°Π΄Ρ€ΠΆΠ°Ρ˜Π° Gd Ρƒ структури, Ρ€Π΅Π΄ΡƒΠΊΡ†ΠΈΡ˜ΠΈ Mn4+ Π΄ΠΎ Mn3+ ΠΈΠ·Π±ΠΎΠ³ присуство Π²Π°ΠΊΠ°Π½Ρ†ΠΈΡ˜Π°...In this thesis, examined the optimal method for obtaining nano powders -calcium manganese oxide doped with gadolinium ions. The aim of the research is toexamine the appropriate precursors that are suitable to obtain pure nano powders ofperovskite manganite structure, as well as single-phase solid solutions with a perovskitestructure. As a suitable method used is a modified glycine nitrate method, a precursornitrates and acetates of the respective metals. Modification of the procedure wasperformed by partial replacement of nitrates by acetates, in order to control the burn-upreaction. Examined the relationship of various precursors, which give nanosizedpowders have a small loss in reactions. Synthesized four nanopowders using modifiedglycine nitrate procedure with the following nominal composition: Ca0.95Gd0.05MnO3,Ca0.9Gd0.1MnO3, Ca0.85Gd0.15MnO3 and Ca0.8Gd0.2MnO3. The resulting powders werefurther calcined in the temperature range of 850 oC to 950 oC 10 min. The temperaturerange in which they were considered calcined samples, obtained using differentialthermal analysis (DTA). Experimentally determined optimal sintering temperature andthey are in the range of 1350 to 1450 oC.Structural and microstructural characterization of Ca1-xGdxMnO3 (x= 0.05; 0.1;0.15; 0.2) nanopowders were performed by XRPD diffraction tehnique and Rietveldrefinement. Monophase composition of all samples was revealed using XRPDdiffraction and Rietveld refinement, Pnma space group but this, that allperovskitephases are deformed as a result of doping with Gd3+. Unit cell parametersanalysis showed that the increase of unit cell parameters and changes in the averagelength Mn─O bonds comes from the increasing content of Gd in the structure, reductionof Mn4+ to Mn3+ and the presence of vacancies..

    Synthesis, structural and magnetic properties of Ca1-xGdxMnO3 nanopowders

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    Π£ ΠΎΠΊΠ²ΠΈΡ€Ρƒ ΠΎΠ²Π΅ докторскС Ρ‚Π΅Π·Π΅, испитиванС су ΠΎΠΏΡ‚ΠΈΠΌΠ°Π»Π½Π΅ ΠΌΠ΅Ρ‚ΠΎΠ΄Π΅ Π·Π° Π΄ΠΎΠ±ΠΈΡ˜Π°ΡšΠ΅Π½Π°Π½ΠΎΠΏΡ€Π°Ρ…Π° – ΠΊΠ°Π»Ρ†ΠΈΡ˜ΡƒΠΌ манганског оксида Π΄ΠΎΠΏΠΈΡ€Π°Π½ΠΎΠ³ јонима Π³Π°Π΄ΠΎΠ»ΠΈΠ½ΠΈΡ˜ΡƒΠΌΠ°. Π¦ΠΈΡ™ΠΈΡΡ‚Ρ€Π°ΠΆΠΈΠ²Π°ΡšΠ° јС ΠΈΡΠΏΠΈΡ‚ΠΈΠ²Π°ΡšΠ΅ ΠΎΠ΄Π³ΠΎΠ²Π°Ρ€Π°Ρ˜ΡƒΡ›ΠΈΡ… прСкурсора који су подСсни Π΄Π° ΡΠ΅Π΄ΠΎΠ±ΠΈΡ˜Ρƒ чисти Π½Π°Π½ΠΎ ΠΏΡ€Π°Ρ…ΠΎΠ²ΠΈ ΠΌΠ°Π½Π³Π°Π½ΠΈΡ‚Π° са пСровскитском структуром, ΠΊΠ°ΠΎ ΠΈΠΌΠΎΠ½ΠΎΡ„Π°Π·Π½ΠΈ чврсти раствори са пСровскитском структуром. Као подСсан ΠΌΠ΅Ρ‚ΠΎΠ΄ΠΊΠΎΡ€ΠΈΡˆΡ›Π΅Π½Π° јС ΠΌΠΎΠ΄ΠΈΡ„ΠΈΠΊΠΎΠ²Π°Π½Π° Π³Π»ΠΈΡ†ΠΈΠ½ Π½ΠΈΡ‚Ρ€Π°Ρ‚Π½Π° ΠΌΠ΅Ρ‚ΠΎΠ΄Π°, Π° ΠΎΠ΄ прСкурсора Π½ΠΈΡ‚Ρ€Π°Ρ‚ΠΈ ΠΈΠ°Ρ†Π΅Ρ‚Π°Ρ‚ΠΈ ΠΎΠ΄Π³ΠΎΠ²Π°Ρ€Π°Ρ˜ΡƒΡ›ΠΈΡ… ΠΌΠ΅Ρ‚Π°Π»Π°. ΠœΠΎΠ΄ΠΈΡ„ΠΈΠΊΠ°Ρ†ΠΈΡ˜Π° Π³Π»ΠΈΡ†ΠΈΠ½ Π½ΠΈΡ‚Ρ€Π°Ρ‚Π½Π΅ ΠΌΠ΅Ρ‚ΠΎΠ΄Π΅ сС односина Π΄Π΅Π»ΠΈΠΌΠΈΡ‡Π½Ρƒ Π·Π°ΠΌΠ΅Π½Ρƒ Π½ΠΈΡ‚Ρ€Π°Ρ‚Π° Π°Ρ†Π΅Ρ‚Π°Ρ‚ΠΈΠΌΠ°, Ρ‡ΠΈΠΌΠ΅ јС ΡƒΠ±Π»Π°ΠΆΠ΅Π½Π° бурност Ρ€Π΅Π°ΠΊΡ†ΠΈΡ˜Π΅.Π˜ΡΠΏΠΈΡ‚Π°Π½ јС Ρ€Π°Π·Π»ΠΈΡ‡ΠΈΡ‚ΠΈ однос прСкурсора, који Π΄Π°Ρ˜Ρƒ наночСстичнС ΠΏΡ€Π°Ρ…ΠΎΠ²Π΅ ΠΈ ΠΈΠΌΠ°Ρ˜ΡƒΠΌΠ°Π»ΠΈ Π³ΡƒΠ±ΠΈΡ‚Π°ΠΊ ΠΏΡ€ΠΈ Ρ€Π΅Π°ΠΊΡ†ΠΈΡ˜Π°ΠΌΠ°. БинтСтисано јС ΡƒΠΊΡƒΠΏΠ½ΠΎ Ρ‡Π΅Ρ‚ΠΈΡ€ΠΈ Π½Π°Π½ΠΎΠΏΡ€Π°Ρ…Π° ΠΏΡ€ΠΈΠΌΠ΅Π½ΠΎΠΌΠΌΠΎΠ΄ΠΈΡ„ΠΈΠΊΠΎΠ²Π°Π½Π΅ Π³Π»ΠΈΡ†ΠΈΠ½ Π½ΠΈΡ‚Ρ€Π°Ρ‚Π½Π΅ ΠΌΠ΅Ρ‚ΠΎΠ΄Π΅ са слСдСћим Π½ΠΎΠΌΠΈΠ½Π°Π»Π½ΠΈΠΌ саставом:Ca0,95Gd0,05MnO3; Ca0,9Gd0,1MnO3; Ca0,85Gd0,15MnO3; Ca0,8Gd0,2MnO3. Π”ΠΎΠ±ΠΈΡ˜Π΅Π½ΠΈΠΏΡ€Π°Ρ…ΠΎΠ²ΠΈ су Π΄Π°Ρ™Π΅ калцинисани Ρƒ Ρ‚Π΅ΠΌΠΏΠ΅Ρ€Π°Ρ‚ΡƒΡ€Π½ΠΎΠΌ ΠΈΠ½Ρ‚Π΅Ρ€Π²Π°Π»Ρƒ ΠΎΠ΄ 850 ΠΎΠ‘ Π΄ΠΎ 950 ΠΎΠ‘ 10min. Π’Π΅ΠΌΠΏΠ΅Ρ€Π°Ρ‚ΡƒΡ€Π½ΠΈ опсСг Ρƒ ΠΊΠΎΠΌΠ΅ су посматрани калцинисани ΡƒΠ·ΠΎΡ€Ρ†ΠΈ, добијСн Ρ˜Π΅ΠΊΠΎΡ€ΠΈΡˆΡ›Π΅ΡšΠ΅ΠΌ Π΄ΠΈΡ„Π΅Ρ€Π΅Π½Ρ†ΠΈΡ˜Π°Π»Π½ΠΎ Ρ‚Π΅Ρ€ΠΌΠΈΡ˜ΡΠΊΠ΅ Π°Π½Π°Π»ΠΈΠ·Π΅ (ДВА). ЕкспСримСнтално суодрСђСнС ΠΎΠΏΡ‚ΠΈΠΌΠ°Π»Π½Π΅ Ρ‚Π΅ΠΌΠΏΠ΅Ρ€Π°Ρ‚ΡƒΡ€Π΅ ΡΠΈΠ½Ρ‚Π΅Ρ€ΠΎΠ²Π°ΡšΠ° ΠΈ Π½Π°Π»Π°Π·Π΅ сС Ρƒ опсСгу ΠΎΠ΄ 1350 Π΄ΠΎ1450 ΠΎΠ‘.ΠœΠ΅Ρ‚ΠΎΠ΄ΠΎΠΌ рСндгСнскС Π΄ΠΈΡ„Ρ€Π°ΠΊΡ†ΠΈΠΎΠ½Π΅ Π°Π½Π°Π»ΠΈΠ·Π΅ ΠΈ Π ΠΈΡ‚Π²Π΅Π»Π΄ΠΎΠ²ΠΎΠ³ ΡΡ‚Ρ€ΡƒΠΊΡ‚ΡƒΡ€Π½ΠΎΠ³ΡƒΡ‚Π°Ρ‡ΡšΠ°Π²Π°ΡšΠ° ΠΈΠ·Π²Ρ€ΡˆΠ΅Π½Π° јС структурна ΠΈ микроструктурна ΠΊΠ°Ρ€Π°ΠΊΡ‚Π΅Ρ€ΠΈΠ·Π°Ρ†ΠΈΡ˜Π°Π‘Π°1-xGdxMnO3 (Ρ… = 0,05; 0,1; 0,15; 0,2) Π½Π°Π½ΠΎΠΏΡ€Π°Ρ…ΠΎΠ²Π°. На Ρ‚Π°Ρ˜ Π½Π°Ρ‡ΠΈΠ½ јС ΡƒΡ‚Π²Ρ€Ρ’Π΅Π½ΠΌΠΎΠ½ΠΎΡ„Π°Π·Π°Π½ састав свих ΡƒΠ·ΠΎΡ€Π°ΠΊΠ°, просторна Π³Ρ€ΡƒΠΏΠ° Pnma Π°Π»ΠΈ ΠΈ Ρ‚ΠΎ, Π΄Π° су овипСровскити ΡƒΠ³Ρ€Π°Π΄ΡšΠΎΠΌ Gd3+ дСформисани. Анализом ΠΏΠ°Ρ€Π°ΠΌΠ΅Ρ‚Π°Ρ€Π° Ρ˜Π΅Π΄ΠΈΠ½ΠΈΡ‡Π½Π΅ Ρ›Π΅Π»ΠΈΡ˜Π΅ΡƒΡΡ‚Π°Π½ΠΎΠ²Ρ™Π΅Π½ΠΎ јС Π΄Π° ΠΏΠΎΠ²Π΅Ρ›Π°ΡšΠ΅ ΠΏΠ°Ρ€Π°ΠΌΠ΅Ρ‚Π°Ρ€Π° ΠΈ ΠΏΡ€ΠΎΠΌΠ΅Π½Π° Ρƒ просСчним Π΄ΡƒΠΆΠΈΠ½Π°ΠΌΠ° Mnβ”€ΠžΠ²Π΅Π·Π° Π½Π°ΡΡ‚Π°Ρ˜Π΅ услСд ΠΏΠΎΠ²Π΅Ρ›Π°ΡšΠ° ΡΠ°Π΄Ρ€ΠΆΠ°Ρ˜Π° Gd Ρƒ структури, Ρ€Π΅Π΄ΡƒΠΊΡ†ΠΈΡ˜ΠΈ Mn4+ Π΄ΠΎ Mn3+ ΠΈΠ·Π±ΠΎΠ³ присуство Π²Π°ΠΊΠ°Π½Ρ†ΠΈΡ˜Π°...In this thesis, examined the optimal method for obtaining nano powders -calcium manganese oxide doped with gadolinium ions. The aim of the research is toexamine the appropriate precursors that are suitable to obtain pure nano powders ofperovskite manganite structure, as well as single-phase solid solutions with a perovskitestructure. As a suitable method used is a modified glycine nitrate method, a precursornitrates and acetates of the respective metals. Modification of the procedure wasperformed by partial replacement of nitrates by acetates, in order to control the burn-upreaction. Examined the relationship of various precursors, which give nanosizedpowders have a small loss in reactions. Synthesized four nanopowders using modifiedglycine nitrate procedure with the following nominal composition: Ca0.95Gd0.05MnO3,Ca0.9Gd0.1MnO3, Ca0.85Gd0.15MnO3 and Ca0.8Gd0.2MnO3. The resulting powders werefurther calcined in the temperature range of 850 oC to 950 oC 10 min. The temperaturerange in which they were considered calcined samples, obtained using differentialthermal analysis (DTA). Experimentally determined optimal sintering temperature andthey are in the range of 1350 to 1450 oC.Structural and microstructural characterization of Ca1-xGdxMnO3 (x= 0.05; 0.1;0.15; 0.2) nanopowders were performed by XRPD diffraction tehnique and Rietveldrefinement. Monophase composition of all samples was revealed using XRPDdiffraction and Rietveld refinement, Pnma space group but this, that allperovskitephases are deformed as a result of doping with Gd3+. Unit cell parametersanalysis showed that the increase of unit cell parameters and changes in the averagelength Mn─O bonds comes from the increasing content of Gd in the structure, reductionof Mn4+ to Mn3+ and the presence of vacancies..
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