Orthorhombic YBCO-123 ceramic oxide superconductor: Structural, resistive and thermal properties
| Autor: | Petre Rotaru, Petr Nozar, Ana Harabor, Andrei Rotaru, N. A. Harabor |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Materials science
Analytical chemistry Oxide chemistry.chemical_element 02 engineering and technology 01 natural sciences Endothermic process symbols.namesake chemistry.chemical_compound Oxide superconductors X-ray diffraction methods Thermal properties D2 diffusion model Electrical conductivity Activation energy Electrical resistivity and conductivity 0103 physical sciences Materials Chemistry Ceramic 010302 applied physics Arrhenius equation Argon Process Chemistry and Technology Atmospheric temperature range 021001 nanoscience & nanotechnology Surfaces Coatings and Films Electronic Optical and Magnetic Materials chemistry visual_art Ceramics and Composites symbols visual_art.visual_art_medium Orthorhombic crystal system 0210 nano-technology |
| Zdroj: | Ceramics international 45 (2019): 2899–2907. doi:10.1016/j.ceramint.2018.07.272 info:cnr-pdr/source/autori:Harabor A.; Rotaru P.; Harabor N.A.; Nozar P.; Rotaru A./titolo:Orthorhombic YBCO-123 ceramic oxide superconductor: Structural, resistive and thermal properties/doi:10.1016%2Fj.ceramint.2018.07.272/rivista:Ceramics international/anno:2019/pagina_da:2899/pagina_a:2907/intervallo_pagine:2899–2907/volume:45 |
| ISSN: | 0272-8842 |
| Popis: | Two YBa 2 Cu 3 O 7-x materials (YBCO-I sintered at 1000 °C, and YBCO-II sintered at 960 °C and following special cooling programs) belonging to the orthorhombic system were obtained. YBCO-I has a complete volume texture, while for YBCO-II it is only on sample surface. On heating in air (with 10 K min −1 in the temperature range 20–1000 °C), two endothermic processes are recorded on DSC curves (of YBCO-II) and they are due to oxygen diffusion from O1 to O5 sites, and then to the release into the environment; second endothermic effect is attributed to the decomposition reaction. Different behaviour is encountered on heating in argon: an endothermic process in two steps; continuous mass decrease (oxygen loss) during argon cooling is recorded on the thermogravimetric curve. In argon atmosphere, the obtained material shall correspond to the chemical composition: YBa 2 Cu 3 O 6.77 , while in air atmosphere, the maximal composition than may be obtained is: YBa 2 Cu 3 O 6.88 . The barrier energies from Arrhenius plots of resistivity vs. temperature (91–93 K) show 2D (YBCO-I) and 3D (YBCO-II) behaviour for the thermally activated flow of melted vortex lattice, below the critical temperature. |
| Databáze: | OpenAIRE |
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