Effect of composition and oxygen content on the microwave properties of evaporated Y-Ba-Cu-O thin films
Effect of composition and oxygen content on the microwave properties of evaporated Y-Ba-Cu-O thin films
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DOI：
10.1109/77.402769
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发表时间：
1995-06
影响因子：
1.8
通讯作者：
N. G. Chew;J. A. Edwards;R. Humphreys;J. Satchell;S. W. Goodyear;B. Dew;N. Exon;S. Hensen;M. Lenkens;G. Muller;S. Orbach-Werbig
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文献类型：
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作者：
N. G. Chew;J. A. Edwards;R. Humphreys;J. Satchell;S. W. Goodyear;B. Dew;N. Exon;S. Hensen;M. Lenkens;G. Muller;S. Orbach-Werbig
在原子氧存在下，用电子束蒸发法生长了YBa/sub 2/Cu/sub 3/O/sub 7-x/薄膜，其阳离子组成变化很小。接近化学计量组成或具有过量钇的薄膜是光滑的，而具有过量钡的薄膜则基本上是粗糙的。在微波和直流性能上的阳离子组合物的这些差异的影响是由相关的膜形态的大的变化。这决定了氧化状态，从而决定了超导体在生长状态和在炉中退火或用原子氧退火后的电学性质。对于所有的膜之间的渗透深度，电阻率和C-晶格参数，都随着氧含量的增加而降低的强相关性。在我们的标准生长方案中，在较高的氧含量下，薄膜过掺杂，并且T/sub c/福尔斯随着氧含量的增加而下降。
Thin films of YBa/sub 2/Cu/sub 3/O/sub 7-x/ have been grown by electron beam evaporation of the metals in the presence of atomic oxygen, with small systematic variations in cation composition. Films grown close to the stoichiometric composition or with excess yttrium are smooth while those with excess barium are substantially rougher. The effect of these differences in cation composition on both microwave and dc properties is dominated by the associated large changes in film morphology. This determines the oxygenation state, and hence the electrical properties, of the superconductor both in the as-grown state and after annealing in a furnace or with atomic oxygen. For all films a strong correlation is found between penetration depth, resistivity and c-lattice parameter which all decrease with increasing oxygen content. In our standard growth regime and at higher oxygen contents the films are overdoped and T/sub c/ falls with increasing oxygen content.>