Resonant photoemission spectroscopy study of impurity-induced melting in Cr- and Ru-doped Nd1/2A1/2MnO3 (A=Ca, Sr)

Abstract

Electronic structures of very dilute Cr- or Ru-doped Nd1/2A1/2MnO3 (NAMO) (A=Ca, Sr) manganites have been investigated using the Mn and Cr 2p→3d resonant photoemission spectroscopy (PES). All the Cr- and Ru-doped NAMO systems exhibit the clear metallic Fermi edges in the Mn eg spectra near EF, consistent with their metallic ground states. The Cr 3d states with [Formula presented] configuration are at ∼1.3 eV below EF, and the Cr eg states do not participate in the formation of the band near EF. Cr- and Ru-induced ferromagnetism and insulator-to-metal transitions can be understood based on their measured electronic structures. © 2003 The American Physical Society.