On Electronegativity of the High-T_c Oxide Superconductor

Using a very useful quantity in physics and chemistry, the electronegativity, we have found that for nearly 70 high-T_c oxide superconductors (HTOS), the average electronegativity is in a narrow range 2.5-2.7. The difference of bond character between the HTOS and the conventional superconductors has been discussed. Finally, two categories of superconductors in terms of the group average electronegativity are suggested.