Surface superconductivity and structural analysis of YC2 single crystals encapsulated in carbon nanocages
Surface superconductivity and structural analysis of YC2 single crystals encapsulated in carbon nanocages
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DOI：
10.1063/1.1510946
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发表时间：
2002-10
影响因子：
3.2
通讯作者：
Y. Yosida
中科院分区：
文献类型：
--
作者：
Y. Yosida
报道了封装在碳纳米笼中的 YC2 单晶在 2 至 10 K 温度和高达 5 T 的外加磁场中的磁化强度测量以及 293 K 下的 X 射线粉末衍射测量。 Tc 附近磁化曲线中的最高临界场与表面超导的成核场 Hc3 非常一致。 Hc3(2 K) 随着平均粒径的减小而增加，显示了我们的纳米晶体的小粒径的影响。没有发现金兹堡临界区明显的尺寸依赖性，并表明这是通过 YC2 晶体和最内部纳米笼之间的接触部分抑制表面超导性的证据。 CaC2 模型的 Rietveld 精修得出的结构参数与大块 YC2 的结构参数一致。
The magnetization measurements in the temperatures between 2 and 10 K and in the applied fields up to 5 T and x-ray powder diffraction measurement at 293 K for YC2 single crystals encapsulated in carbon nanocages are reported. The highest critical field in the magnetization curve near Tc is in excellent agreement with the nucleation field Hc3 for surface superconductivity. Hc3(2 K), increasing with decreasing mean particle diameter, shows an effect of small-particle size of our nanocrystals. No appreciable size dependence of the Ginzburg critical region is found and suggested to be evidence of the partial suppression of surface superconductivity through the contact between YC2 crystals and the innermost nanocages. Structural parameters derived from the Rietveld refinement of the CaC2 model are consistent with those of the bulk YC2.