الفهرس 
Abstract
Samole preparationOnly 14 pages are availabe for public view
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Abstract
We report the results of a Mossbauer effect study of layered perovskites La2CuO4, RE2CuO4 (RE = Pr, Nd, Sm, Eu, and Gd), PrBa2Cu3O7-6, YBa2Cu3Ox and laser ableted YBa2cu30x film on LaAl03 single crystal substrate. The samples of these compounds were ceramic discs or powder, prepared by the coprecipitation method and/or single crystals (size - 1 mm3 ) grown from PbO and CuO based fluxes. These samples have been doped with either coS7 for emission Mossbauer studies, or with pe S7 for conventional absorber Mossbauer experiments. M6ssbauer spectra of co57 -doped single crystal have been recorded at 78 K and at 295 K for different source orientations. Measurements made at 295 K show that the sign of the electric field gradient (EFG) is positive and that the EFG is tilted at with respect to the crystalline c-axis. It is also found that the magnitude of the quadrupole splitting is 1.76 mm/s. In the antiferromagnetic regime (78 K) measurements show a Fe hyperfine field of 460 KOe which lies in the, basal plane of the crystal structure. In addition, the nuclear quadrupole interaction energy as a function of temperature on ceramic sample does not show evidence of any quadrupole anomaly below 150 K, as reported.