Comment on “Is Nd2−xCexCuO4 an electron-superconductor?”

A critical comment was made to the electron energy-loss spectroscopy [Z. Phys. B-Condensed Matter75, 421 (1989)] which questionedn-type superconductivity in Nd2−xCexCuO4. Comparative oxygen-K absorption and oxygen 1s photoemission spectroscopies for Nd2−xCexCuO4 and Bi2Sr2CaCu2O8 have shown that these two superconductors are classified into two different categories.