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Influence of noble earth's elements on Bi based high temperature superconductors phase transition.
Šilhavý, Miroslav ; Havlica, Jaromír (referee) ; Ptáček, Petr (advisor)
The thesis is focused on high-temperature superconducting (HTS) ceramics series of bismuth. Specifically, there is studied Bi2Sr2CaCu2O8+x phase, known as the 2212 phase. The theoretical part describes the basic properties of superconductivity and superconductors, the properties of cuprate ceramics and description of LBCO, YBCO and BSCCO structures. The experimental part deals with the preparation of the precursor own Bi-2212 phase. It is synthesized by a process called sol-gel. Feedstock Bi2O3, CaCO3, SrCO3 and CuSO4 was dissolved in HNO3 and transferred to a complex with ethylenediaminetetraacetic acid (EDTA, Chelaton II). With NH3 pH > 9 was maintained due to the stability of complex. The obtained gel was concentrated, calcinated in a furnace at 860 °C and crushed into powder. Pure powder was subjected to analysis dipping microscope, SEM, XRD, FT-IR, TG-DTA at different atmospheres argon, oxygen and air. Then 1 wt.% of the oxide (La, Y, Sc, Sm) was added to part of the powder precursor and the samples were examined using TG-DTA.
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Influence of noble earth's elements on Bi based high temperature superconductors phase transition.
Šilhavý, Miroslav ; Havlica, Jaromír (referee) ; Ptáček, Petr (advisor)
The thesis is focused on high-temperature superconducting (HTS) ceramics series of bismuth. Specifically, there is studied Bi2Sr2CaCu2O8+x phase, known as the 2212 phase. The theoretical part describes the basic properties of superconductivity and superconductors, the properties of cuprate ceramics and description of LBCO, YBCO and BSCCO structures. The experimental part deals with the preparation of the precursor own Bi-2212 phase. It is synthesized by a process called sol-gel. Feedstock Bi2O3, CaCO3, SrCO3 and CuSO4 was dissolved in HNO3 and transferred to a complex with ethylenediaminetetraacetic acid (EDTA, Chelaton II). With NH3 pH > 9 was maintained due to the stability of complex. The obtained gel was concentrated, calcinated in a furnace at 860 °C and crushed into powder. Pure powder was subjected to analysis dipping microscope, SEM, XRD, FT-IR, TG-DTA at different atmospheres argon, oxygen and air. Then 1 wt.% of the oxide (La, Y, Sc, Sm) was added to part of the powder precursor and the samples were examined using TG-DTA.
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