Heat Treatment of Nd1+xBa2-xCu3O7-δ Superconductors
来源期刊：JOURNAL OF RARE EARTHS2003年第2期
论文作者：司平占 苏大和 樊占国
Key words：inorganic nonmetallic materials; Nd1+xBa2-xCu3O7-δ superconductors; heat treatment; solid solubility; superconductivity; rare earths;
Abstract: Two kinds of Nd1+xBa2-xCu3O7-δ, the sintered samples and zone melted samples, were treated in pure Ar at 950 ℃. The substitution of Nd ions for Ba ions in the Nd1+xBa2-xCu3O7-δ before and after the heat treatment was investigated by XRD. In order to know the effects of heat treatment, the Tc and Jc of samples with and without the heat treatment in Ar were comparatively studied. The results show that the substitution of Nd for Ba decreases, whereas Tc and Jc increase after the treatment. The Nd1+xBa2-xCu3O7-δ samples were oxygenated in pure oxygen at 300 ℃. Based on the XRD spectra it was found that the samples with x＜0.4 can transform from tetragonal phase into orthorhombic phase after the oxygenation, whereas in the sample with x＞0.4 no phase transition occurs even after a long time oxygenation.
司平占1，苏大和2，樊占国3
(1.Institute for Metal Research, Chinese Academy of Sciences, Shenyang 110016, China;
2.Myongji University, Yongin 449-728, South Korea;
3.School of Material Science and Metallurgy, Northeastern University, Shenyang 110006, China)
Abstract:Two kinds of Nd1+xBa2-xCu3O7-δ, the sintered samples and zone melted samples, were treated in pure Ar at 950 ℃. The substitution of Nd ions for Ba ions in the Nd1+xBa2-xCu3O7-δ before and after the heat treatment was investigated by XRD. In order to know the effects of heat treatment, the Tc and Jc of samples with and without the heat treatment in Ar were comparatively studied. The results show that the substitution of Nd for Ba decreases, whereas Tc and Jc increase after the treatment. The Nd1+xBa2-xCu3O7-δ samples were oxygenated in pure oxygen at 300 ℃. Based on the XRD spectra it was found that the samples with x＜0.4 can transform from tetragonal phase into orthorhombic phase after the oxygenation, whereas in the sample with x＞0.4 no phase transition occurs even after a long time oxygenation.
Key words:inorganic nonmetallic materials; Nd1+xBa2-xCu3O7-δ superconductors; heat treatment; solid solubility; superconductivity; rare earths;
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