OPTICAL EVIDENCE FOR THE DYNAMIC JAHN-TELLER EFFECT IN ND0.7SR0.3MNO3

The optical properties of Nd0.7Sr0.3MnO3 thin films have been studied over a broad spectral range, at temperatures down to 15 K and magnetic fields up to 8.9 T. A large transfer of spectral weight from high ene rgy to low energy occurs as this material is cooled into the ferromagn etic phase, or as the magnetic field is increased near the phase bound ary. The optical data are found to be consistent with models that incl ude both the double-exchange interaction and the dynamic Jahn-Teller e ffect on the Mn3+ e(g) levels.