Study of the behavior of the ρ-T curve of YBa2Cu3Oy during synthesis in ambient air

The relation of the resistivity vs. synthesizing temperature of YBa2Cu3Oy samples was studied while the material being was prepared under atmospheric conditions. A set of ρ-T curves was obtained for the entire process. At the end of the last sintering step the resistivity values of the YBa2Cu3Oy sample was ρ1233=5.64x10-2 Ω cm at 960 deg. C, and ρ300=4.32x10-3 Ω cm at room temperature. The ρ-T curves for the heating stages also show that the formation temperature of YBa2Cu3Oy crystal grains and the re-crystallization temperature are in the range of 480-870 deg. C. When a YBa2Cu3Oy sample was reheated, the ρ-T curve also shown that the orthorhombic-tetragonal phase transformation of YBa2Cu3Oy sample occurred at 690 deg. C