The effects of nonstoichiometry in high - Tc superconducting properties of $YBa_2Cu_3+xO_7-\delta$

Özet

Polycrystalline samples of high $T_c$ superconductor $YBa_2Cu_{3 +x}O_{7 - \delta}$ with $0 \leqslant x \leqslant 0.5$ were grown. The effects of nonstoichiometry on the resistance slope above transition temperature $T_c$ and X-ray diffraction patterns for these samples were investigated. In the diffraction patterns obtained, apart from some new features in the peaks, these polycrystalline samples show predominantly 123 phase.