Magnons and phonons inNd2CuO4

Antiferromagnetic magnons ${\mathrm{Nd}}_2$ ${\mathrm{CuO}}_4$, which is the mother material of the electron superconductor (${\mathrm{Nd}}_{1\mathrm{-}\mathrm{x}}$ ${\mathrm{Ce}}_{\mathrm{x}}$ ${)}_2$ ${\mathrm{CuO}}_{4\mathrm{-}\mathrm{y}}$, are observed by Raman scattering. The effective exchange integral estimated from the two-magnon peak energy is 1070 ${\mathrm{cm}}^{\mathrm{-}1}$, which is unexpectedly large in spite of the large Cu-Cu atomic distance compared with those in other superconducting oxides. Lattice vibrations are also investigated. A large two-phonon peak due to the intralayer breathing mode is observed at 1178 ${\mathrm{cm}}^{\mathrm{-}1}$. .AE