Preparation of c-axis oriented YBa2Cu3O7 polycrystalline ceramics by sol-gel method

YBa2Cu3O7 powders and ceramics with c-axis preferred orientation were synthesized by sol-gel method. The pure phase powders were obtained when calcined between 800 and 930 degrees C, and the ceramics were sintered at 950 degrees C. It was found that c-axis orientated ceramics were obtained only when the powders were calcined at 930 degrees C. The X-ray diffraction patterns show that the relative intensities of c-axis (00l) peaks are much stronger than that of the standard pattern. The surface morphology own an obvious layered structure and the grains are platelike grown. The transition temperature T-C(onset) is 93.67 K with a transition width Delta T-c of 2.1 K. (C) 2015 Elsevier B.V. All rights reserved.