运用高压技术设计和研制超导材料新体系  

New superconducting materials discovered via high pressures technology

作　　者：靳常青[1,2] 

机构地区：[1]中国科学院物理研究所,北京100190 [2]中国科学院大学,北京100049

出　　处：《科学通报》2017年第34期3947-3954,共8页Chinese Science Bulletin

基　　金：国家自然科学基金重大项目(11220101003);国家重点研发计划(2017YFA0302901)资助

摘　　要：本文介绍运用高压技术发现的几类超导材料新体系,包括(1)顶角氧有序型(简称"顶角氧"系)、Cu12(n-1)n(简称"铜系")和Cl2(n-1)n(简称"卤系")等3类铜基超导材料体系:它们只含铜和碱土氧化物,是构成铜基超导的最简单组分;这些体系在常压的超导温度(T_c)可媲美Y123、Bi系、Hg系等组分复杂的铜基超导材料,"铜系"的T_c可高达123 K,Cl212是第1个含卤素的液氮温区超导体;"顶角氧"有序化将同结构的铜基超导材料的转变温度提高1倍以上,刷新了单层铜氧面结构铜基超导材料的Tc记录;新体系的高温载流特性名列前茅,"铜系"在液氮温区的临界电流特性优于Bi系、Hg系,与Y123相当.(2)铁基超导材料主要体系之一的"111"体系:"111"体系组分结构简单,易于揭示铁基超导核心要素.它的解离面无极性,表面和体态结果严格一致,为通过角分辨光电子能谱(ARPES)和扫描隧道显微镜(STM)等先进表征技术揭示铁基超导的本征物性提供了理想结构载体.主要成员LiFeAs具有无Fermi面嵌套的重要特征,表明Fermi面嵌套并非实现铁基超导必要条件,扭转了此前基于铁基其他体系的费米面嵌套对机理的流行认识.(3)Bi_2Te_3拓扑化合物超导体:实现无需化学掺杂引入载流子,揭示了国际上首个压力诱导的拓扑化合物超导.In this study, we primarily select the author＇s research to briefly introduce the various superconducting materials that are synthesized using high pressures. Superconducting systems included are ranging from cuprates, iron-based materials, to topological compounds. They are fabricated using： ＂self-high-pressure oxidization＂, which is produced using the chemical composition of the synthesized material itself rather than using traditional alien oxidizers; ＂inner pressure effects＂, which are generated using the atomic size changes; and a ＂pure doping mechanism＂ that is induced using a pressure-induced charge transfer, respectively. We focus on three categories of superconductors in our investigation.（1） Apical oxygen ordered cuprate superconductors that reach the highest Tc for the monolayered cuprate superconductors, Cu12（n-1）n homologues series cuprate superconductors having a Tc of up to 123 K, and a Cl2（n-1）n homologues series cuprate superconductor that is the first halogen-containing superconducting system having a Tc higher than liquid nitrogen： These cuprate superconductors comprise only copper and alkaline earth metal oxides, which are the simplest reagents that are necessary to form high Tc cuprates. However, those high pressure synthesized materials exhibit very high Tc that usually can only be realized in cuprates superconductors with complex compositions if prepared at ambient condition such as YBCO123, Bi22（n-1）n, or Hg12（n-1）n. The new superconductors exhibit excellent critical electrical current density as a function of temperature, especially at high temperatures. They show superior properties than the Bi/Hg cuprate homologues superconductors and are comparable to the classical Y123.（2） The ＂111＂ iron-based superconducting system： This system features neutral-charged cleaved fresh surfaces that are perfect for experimental studies based on angle resolved photoemission electron spectroscopy（ARPES） or scanning transmission microscopy（STM）. Compa

关 键 词：“111”铁基超导材料体系 “顶角氧有序型”铜基超导材料体系 “铜系”铜基超导材料体系 “卤系”铜基超导材料体系 拓扑化合物超导体 高压高温合成技术 内压缩 自氧化高氧压 

分 类 号：O511.3[一般工业技术—材料科学与工程]