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Abstract: The research studied the effect of annealing temperature on phase and thermoelectric properties of YBa2Cu3O7-x ceramics synthesized by hot pressing method. The hot-pressing condition involved the applied pressure of 70 MPa at 800 C for 1 h under Ar atmosphere. The YBCO ceramic samples were annealed in oxygen atmosphere at 700 and 750 C for 4 h. The XRD patterns of all samples showed single phase of YBCO. The annealing process had the most impact on the electrical conductivity by causing the values to decrease and changed the conduction mechanism from metallic-like to semiconductor-like behavior when the annealing temperature was increased. The trend of ZT therefore followed that of the electrical conductivity which may be attributed to the charged defects present in these samples.
