高温高压合成顶角氧掺杂型高温超导系列

The High Pressure Synthesis and Properties of Apical Oxygen Doped High T_c Superconductors

简要介绍了(Sr,Ca)n+1CunO2n(Cl,O)2,即三元数法的Cl "02n"(或四元数Cl 02(n-1)n)超导系列,简称Cl 系超导体。和通常的高温超导体不同,Cl 系的电荷库由卤化物构成,而非通常的氧化物。即Cl 系的导电区和电荷库由顶角氯连接,根据这一结构特点用"顶角氧"掺杂,高压合成了Tc≈80K的(Sr,Ca)3Cu2O4(Cl,O)2超导体。该化合物具有和全氧化物高温超导体可比的超导性能,表明高温高压合成全新的卤氧超导新材料的潜力,以及开发卤氧化物高温超导体群的研究前景。

The (Sr,Ca)_(n+1)Cu_nO_(2n)(Cl,O)_2superconducting homologous series have been briefly introduced.The emphasis is on the special charge reservoir block of the oxyhalide high T_c superconductror (HTSC),which consists of the halide layer instead of the routine oxide layer.Consequently the apical oxygen related to the p-type HTSC is missed in the compound whereas the apical chlorine bridges the conducting layer and the charge reservoir.In the context a novel hole doping mechanism named'apical oxygen doping'was introduced through partially substituting oxygen for chlorine.This chemical doping leads to an 80 K superconducting transition in the high pressure synthesized double layered (Sr,Ca)_3Cu_2O_4(Cl,O)_2 oxyhalide.Not only the high T_c,the oxyhalide cuprate superconductor also demonstrates the comparable physical properties to those of the full oxide HTSC,indicating the promising prospects to develop new high T_c oxyhalide superconductors.