We report here fluctuation, diamagnetic transition, and FTIR spectra in Bi_1.7Pb_0.30 Sr₂Ca_2-xLa_xCu₃Oy superconductor with various x values (0.00 < x < 0.30). It is found that the magnetic moment is negative for the samples below the onset of diamagnetism in both field cooling (FC) and zero-field cooling (ZFC). Although the magnetic moments are shifted to lower values close to zero as La increases up to 0.30, they are higher for Fc than for ZFC. Furthermore, the onset temperature of diamagnetic transition (T_cM) for La = 0.30 sample is 83 K, which is about 30 K higher than that obtained from resistivity data (T_cR = 53 K). On the other hand, the logarithmic plots of excess conductivity ∆σ and reduced temperature ε for the samples reveal three different exponents corresponding to two crossover temperatures in the slope of each plot. The first exponent occurs in the normal field region (NFR) and its values are 0.30 (3D), 0.50 (3D), 0.20 (3D), and 2.04 (0D). The second exponent occurs in the mean field region (MFR) and its values are 0.75(2D), 0.44 (3D), 0.65 (2D), and 0.36 (3D). The third exponent occurs in the critical field region (CFR) and its values are 0.51 (3D), 0.99 (2D), 0.38 (3D), and 0.65 (2D). Interestingly, the Ginzburg-Landau parameter, critical magnetic fields, and critical current density are gradually increased as La increases up to 0.30, while the interlayer coupling, coherence lengths, anisotropy, and Ginzburg number are decreased. Finally, the FTIR absorption spectra of the samples show nine successive peaks due to O-H, Bi(Pb):2223, residual carbon, SrCo, CaCo₃ and CuO, and M-O, respectively. These results are discussed in terms of the correlation between hole carriers/Cu ions and excess oxygen which are introduced by La through CuO₂ planes of BSCCO superconductors.

PACS: 74.25.Bt74.62.Dh74.62.En74.72.gh

我们在此报告Bi _1.7 Pb _0.30 Sr ₂ Ca _2-x La _x Cu ₃ Oy超导体具有各种x值（0.00  <  x  <  0.30）的波动，反磁跃迁和FTIR光谱。发现在磁场冷却（FC）和零磁场冷却（ZFC）中，样品在低于反磁性开始时的磁矩为负。尽管随着La增大到0.30，磁矩会移至接近零的较低值，但Fc的磁矩要高于ZFC。此外，反磁转变的起始温度（T _cM），对于La = 0.30，样品为83 K，比从电阻率数据（T _cR  = 53 K）获得的样品高约30 K. 在另一方面，过量的导电Δ的对数图σ和降低的温度ε对于样品，在每个曲线的斜率中揭示了三个不同的指数，分别对应两个交叉温度。第一指数出现在法向场区域（NFR）中，其值为0.30（3D），0.50（3D），0.20（3D）和2.04（0D）。第二个指数出现在平均场区域（MFR）中，其值为0.75（2D），0.44（3D），0.65（2D）和0.36（3D）。第三指数出现在临界场区域（CFR）中，其值为0.51（3D），0.99（2D），0.38（3D）和0.65（2D）。有趣的是，随着La增大至0.30，Ginzburg-Landau参数，临界磁场和临界电流密度逐渐增加，而层间耦合，相干长度，各向异性和Ginzburg数则减小。最后，样品的FTIR吸收光谱显示由于OH，Bi（Pb）：2223，₃分别为CuO和MO。根据空穴载流子/ Cu离子与过量氧之间的相关性来讨论这些结果，La经由BSCCO超导体的CuO ₂平面引入。

PACS： 74.25.Bt74.62.Dh74.62.En74.72.gh