Magnetic susceptibility data are presented for the title compounds. All show negative curvature below ~~2T C . Data for grain-aligned YBa2Cu3C>7 are in excellent agreement with a new calculation of the superconducting fluctuation diamagnetism. We infer j-wave pairing and Ginzburg-Landau coherence lengths %ab (0) -13.6 ± 0.8 A and £ c (0) -1.23 ± 0.19 A. Both of the order-parameter bands are found to be essential in the fit. Part of the above negative curvature is inferred to arise from the normal-state background.PACS numbers: 74.20. De, 74.40.+k, 74.65.+n, 74.70.Vy Low-frequency 1 " 6 and microwave 7 conductivity data above T c -92 K as well as heat-capacity 8 data near T c for YBa2Cu3C>7 (Y 1:2:3) indicate that superconducting fluctuations are strong at temperatures T in the vicinity of T c and above, and that the superconductivity is three dimensional. In these measurements, a strong Tdependent background is present and must be subtracted, subject to strong assumptions about the background, in order to extract the fluctuation contributions, leading to ambiguities in the derived microscopic parameters. On the other hand, these fluctuations are also observable as a diamagnetic contribution to the magnetic susceptibility x(T) above r c , 1>9 ' 10 which is otherwise nearly independent of !T. 9 ' 10 Herein, we report #(70 data for a batch of Y 1:2:3 which we believe closely approximate the intrinsic #(70. The data increase monotonically with T up to at least 400 K, and exhibit negative curvature below -200 K. We present the results of a new calculation of the angular dependence of the superconducting fluctuation diamagnetism (SFD) and compare the predictions with our %(T) data for a highly oriented powder with Hllc and H-Lc. This comparison shows that the data are consistent with s-wave pairing and strong SFD up to at least 126 K, and provides quantitative estimates of the r-0 coherence lengths and the effective mass anisotropy. We infer that the background #(70 exhibits negative curvature above T c . Powder #(70 data are also reported for La1.sSro.2CuO3.96 (LaSr 2:1:4) and Bi 2 -*Pb JC Sr2CaCu208+ < 5 (2:2:1:2) for x-0 and x-0.2 which show that the strong SFD is a universal property of the copper-oxide-based materials.Polycrystalline YI^C^OT-^ was prepared from predried Ames Laboratory Y 2 0 3 , 99.999% CuO and 99.9% BaC0 3 at 940 °C for 90 d in air with ten intermediate grindings, followed by heating in O2 at 640 °C for 1 d and oven cooling. From x-ray diffraction analysis, the batch was single phase with y -0. Magnetization M data were obtained in a magnetic field H using a quantum design SQUID magnetometer. The small (corresponding to ==3 ppm Fe/Cu) ferromagnetic im-purity contribution to M was determined from M(H) isotherms and is corrected below. Meissner effect MlH measurements in 77-50 G gave 48% of -1/4TT at 10 K with a zero-field-cooled value in the same H of 127%, both uncorrected for demagnetization factors. The Meissner effect attained 10% and 50% of its maximum value at 91.4 and 88.1 K, respectively. ...