Bulk superconductivity in both tetragonal and orthorhombic solid solutions of (La1-xSrx)2CuO4- delta.
Bulk superconductivity in both tetragonal and orthorhombic solid solutions of (La1-xSrx)2CuO4- delta.
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(La1-xSrx)2CuO4-δ 的四方晶系和斜方晶系固溶体中的体超导性。
DOI：
10.1103/physrevb.48.9689
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发表时间：
1993
期刊：
影响因子：
--
通讯作者：
K. Kitazawa
中科院分区：
文献类型：
--
作者：
T. Nagano;Y. Tomioka;Y. Nakayama;K. Kishio;K. Kitazawa
粉末和烧结球团样品的低场迈斯纳和屏蔽信号的比较测量（La[sub 1[minus][ital x]]Sr[sub [ital x]]）[sub 2]CuO[sub 4[minus][delta]]揭示了在宽范围的Sr成分上存在体超导性，0.0425[le][ital x][le]0.125，在[ITAL x][全等]0.105处的正交到四方相边界上延伸，除了一个狭窄的异常区域[ITAL x]=0.0625。通过喷雾干燥或粉末混合制备与从1100 [degree]C的烧结温度降至500 [degree]C的缓慢冷却或淬火的组合，通过三种不同的方法制备样品，在500 [degree]C下进行氧化退火。只有通过喷雾干燥和缓慢冷却制备的样品才能获得均匀的固溶体。的迈斯纳和屏蔽信号上的Sr含量的依赖关系，在磁场的强度，并在样品的尺寸进行了检查的钉扎效果和穿透深度。
Comparative measurements of low-field Meissner and shielding signals of both powder and sintered pellet samples of (La[sub 1[minus][ital x]]Sr[sub [ital x]])[sub 2]CuO[sub 4[minus][delta]] have revealed that bulk superconductivity is present over a wide range of Sr composition, 0.0425[le][ital x][le]0.125, extending over the orthorhombic-to-tetragonal phase boundary at [ital x][congruent]0.105, except for a narrow anomaly region [ital x]=0.0625. Samples were prepared by three different methods through a combination of spray-drying or powder-mixing preparation with either slow cooling or quenching from the sintering temperature of 1100 [degree]C down to 500 [degree]C, at which oxygenation annealing was performed. Homogeneous solid solutions were obtained only for specimens prepared by spray drying and slow cooling. Dependences of the Meissner and shielding signals on the Sr content, on the intensity of magnetic field, and on the sample size were examined in terms of pinning effect and penetration depth.