Resistivity–temperature characteristics of sol gel YBa 2 Cu 3 O y samples synthesized in flowing oxygen atmosphere

The relationship of resistivity versus synthesizing temperature of sol gel YBa2Cu3Oy samples was studied when prepared under flowing oxygen conditions. A set of high-temperature ρ–T curves was obtained for the whole process. After the sample finished the test measuring, its resistivity was ρ300=9.83 ×10−3Ω.cm at room temperature. The ρ–T curve also showed that the orthorhombic–tetragonal phase transformation of sol-gel YBa2Cu3Oy sample occurred at 581 degrees C for the sample in the rising temperature process, but at 613 degrees C in the cooling process, lower than that of the samples made by using the conventional powder metallurgy methods.