【摘要】 制备了名义组分为La_5-xSr_xCu₅O₃（3-y）（x=0.5,0.75,1.0.1.25,1.5）的多晶样品,测量了5—150K的电阻温度关系,并选择部分样品做了光电子能谱分析。结果发现,在相同的制备条件下,随组分的变化,该系统经历了超导体-半导体-金属（超导体）转变。通过与BaPb_1-xBixO3系统类比对结果进行了计论。更多还原

【Abstract】 The compounds with the nominal compositions of x=0.5, 0.75, 1.0, 1.25, 1.5 of La5-xSrxCu5O5(3-y) were prepared under the same conditions. Resistance of these samples were measured between 5 K and 150 K. The results show that the superconductor-semiconductor-matal (superconductor) transition occurs when the composition of Sr increases from 0.5 to 1.5 in this system. By comparing with BaPb1-xBixO3 system the authers suggest that in this system the strong coupling of electron-phonon interaction makes the lattice unstable and a charge-density-wave distortion likely happens, which would open a semiconductor gap at EF The distortion would be suppressed when the composition of Sr varied, thus the transition from semiconductor to metal (superconductor) is observed.更多还原