Abstract: Chemical experiments and XPS analysis indicate that YBCO superconductor is a relatively strong base, and Ba-O components in YBCO is primarily responsible for its hasicity. Based on the basic property of YBCO, it is suggested that the chemical interactions between YBCO and oxide substrate materials is primarily solid acid-base reactions. The acid-base parameters for substrate materials (MgO, ZrO_2, Al_2O_3 and SiO_2) are calculated and used as a scale for measuring the acidity or basicity of the oxide substrates and for evaluating the YBCO-substrates chemical reactivity. It is found that the chemical reactivity increases with increasing acid-base parameter (or increases with increasing acidity) of the substrate materials. Therefore the chemical reactivity with YBCO increases in the order of MgOThe above rule is also suitable for chemical reaction of BSCCO superconductor with oxide substrate materials.

Key words: YBa₂Cu₃O₇ high-Tc superconductor, Oxide substrate materials, Solid acid-base reaction, Acid-base parameter