Sapphire resonator for the measurement of surface impedance of high-temperature superconducting thin films
Sapphire resonator for the measurement of surface impedance of high-temperature superconducting thin films
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DOI：
10.1063/1.1148106
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发表时间：
1997-05
影响因子：
1.6
通讯作者：
R. J. Ormeno;D. C. Morgan;D. Broun;Shih-Fu Lee;J. Waldram
中科院分区：
文献类型：
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作者：
R. J. Ormeno;D. C. Morgan;D. Broun;Shih-Fu Lee;J. Waldram
本文提出了一种利用冷却蓝宝石圆盘谐振器的谐振腔微扰技术测量高温超导薄膜表面阻抗Zs=Rs+iXs。谐振器在14.4 GHz的TE 011模式下激发，并在样品中感应出a-b平面屏蔽电流。谐振器及其外壳保持在4.2 K，同时样品在可移动的蓝宝石棒上独立加热。样品和谐振器的热隔离使测量几乎没有系统误差，并允许使用超导铌屏蔽。低介电损耗蓝宝石和超导外壳的组合导致数百万的典型无负载品质因数（Q）。移动样品的能力使灵敏度可变，允许测量从5 μΩ到几Ω的表面电阻值。在实验时，通过将样品从谐振器的影响中取出，也可以准确地确定背景损耗。此外，.
A technique using cavity perturbation of a cooled sapphire disk resonator has been developed to measure the surface impedance Zs=Rs+iXs of high-temperature superconducting thin films. The resonator is excited in the TE011 mode at 14.4 GHz and induces a-b plane screening currents in the sample. The resonator and its enclosure are maintained at 4.2 K while the sample is heated independently on a movable sapphire rod. The thermal isolation of the sample and resonator leaves the measurement virtually free of systematic error and permits the use of a superconducting niobium shield. The combination of low dielectric loss sapphire and a superconducting enclosure results in typical unloaded quality factors (Q) of several million. The ability to move the sample makes the sensitivity variable, allowing surface resistance values from 5 μΩ to several Ω to be measured. Background loss can also be accurately determined at the time of experiment by withdrawing the sample from the influence of the resonator. In addition,...