Long-term stability of Hg-based cuprate superconducting thin films prepared from a fluoride precursor
Long-term stability of Hg-based cuprate superconducting thin films prepared from a fluoride precursor
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DOI：
10.1088/0953-2048/15/9/303
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发表时间：
2002-09-01
影响因子：
3.6
通讯作者：
Benacka, S
中科院分区：
文献类型：
--
作者：
Strbíik, V;Plesch, G;Benacka, S
研究了Hg基铜氧化物薄膜超导性能的长期稳定性。以BaF_2、CaF_2和金属Cu为原料，通过热蒸发法制备了空气稳定的Ba-Ca-Cu-（O，F）前驱体。使用X射线衍射图案和它们的电性能的薄膜的稳定性进行了研究。超导转变的主要特征（起始温度和中点温度，以及转变的宽度）在18个月内保持不变，但零电阻率临界温度从117.5 K下降到112 K（约4%），由于延长的低电阻率尾部。Hg基铜氧化物薄膜的良好稳定性可以归因于我们的薄膜的致密特性，没有显示出任何明显的晶界形态。因此，我们假设消除了薄膜退化的主要原因（通常局限于晶界）。
The long-term stability of superconducting properties of Hg-based cuprate thin films is presented. The mercury-based films were synthesized from an air-stable Ba-Ca-Cu-(O, F) precursor prepared by thermal evaporation from fluorides BaF2, CaF2 and metallic Cu. The stability of the films prepared was studied using x-ray diffraction patterns and their electrical properties. The main features of superconducting transition (the onset and the midpoint temperature, as well as the width of transition) remained unchanged during 18 months, but the zero-resistivity critical temperature decreased from 117.5 K to 112 K (about 4%) due to an elongated low-resistivity tail. The good stability of the Hg-based cuprate thin films can be attributed to the dense character of our films that did not show any evident grain boundary morphology. Therefore, we assume that the main reason for the film degradation (as a rule localized at the grain boundaries) was eliminated.