Driving mechanisms behind the various phases in manganese perovskites   revealed by Mn 2p resonance photoemission
  Unusual temperature and doping dependence of the Mn 3d spectral functions of manganese perovskites Nd1-xSrxMnO3 has been revealed by the high-resolution Mn 2p-3d resonance photoemission. The temperature-dependent spectra cannot be explained by any theoretical model currently under debate, while showing evidence for a microscopic and dynamic phase segregation. The experimental results strongly suggest that the competition of both the dynamical and static Jahn-Teller effects with ferromagnetic ordering at high and low temperatures, respectively, is responsible for the actual electronic states. 
A. Sekiyama, H. Fujiwara, A. Higashiya, S. Imada, H. Kuwahara, Y.   Tokura, S. Suga