Tl_2Ba_2CaCu_2O_(8+δ)薄膜在超导凝聚过程中低频区的电磁响应  

The evolution of electromagnetic response at low frequencies with the development of superconducting condensation in Tl_2Ba_2CaCu_2O_(8+δ)

作　　者：马永昌[1,2] 吴玉强[1] 张建柱[1,2] 赵捷[1,3] 刘庆锁[1] 阎少林[4] 

机构地区：[1]天津理工大学材料科学与工程学院,天津300384 [2]天津市光电显示材料与器件重点实验室,天津300384 [3]显示材料与光电器件省部共建教育部重点实验室,天津300384 [4]南开大学信息技术科学学院,天津300071

出　　处：《低温与超导》2010年第11期37-40,45,共5页Cryogenics and Superconductivity

基　　金：国家自然科学基金(10704054)资助

摘　　要：研究了Tl2Ba2CaCu2O8+δ/LaAlO3单晶薄膜的ab平面内电子在超导凝聚过程中的行为,薄膜厚度为3000,转变温度Tc=96K。在凝聚过程中,阻抗谱z(ω,T0)变化剧烈。谱线随温度的变化规律与浅超导区直流压制下的阻抗谱极为相似。随着超导凝聚的加强,谱重从高频区进一步向低频区转移并且导致直流极限下的发散。通过分析,得出超导相变对应了"超流电子岛"从出现到扩大并最终连成"整片超导大陆"这样的过程。我们还测试了薄膜载流下的阻抗谱z(ω,B0),观测到临界电流密度随着超导凝聚的进行而增大。We reported the ab-plane temperature dependent charge dynamics of Tl2Ba2CaCu2O8＋δ/LaAlO3（Tl-2212）single crystal films with thickness 3000 and Tc=96K.In process of the superconducting condensation,the impedance spectrum z（ω,T0）changed considerably.More over,it was very similar with the evolution of the spectrum under various dc bias in the shallow superconducting state.The spectrum weight transfered from high frequency regions to lower frequency range and eventually diverged towards the dc limit.From the analysis,the super fluid islands formed at the beginning and then grow larger,till the formation of a ＇continent＇.The impedance spectrum z（ω,B0）at various dc bias B0 was studied.

关 键 词：凝聚过程 低频 阻抗谱 超导 

分 类 号：O414.1[理学—理论物理]