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.