%0 Journal Article
%T Mn$^{2+}$/Mn$^{3+}$ state of La$_{0.7}$Ce$_{0.3}$MnO$_3$ by oxygen reduction and photodoping
%A Andreas Thiessen
%A Elke Beyreuther
%A Stefan Grafstr£¿m
%A Kathrin D£¿rr
%A Robert Werner
%A Reinhold Kleiner
%A Dieter Koelle
%A Lukas M. Eng
%J Physics
%D 2013
%I arXiv
%R 10.1088/0953-8984/26/4/045502
%X Films of cerium-doped LaMnO$_3$, which has been intensively discussed as an electron-doped counterpart to hole-doped mixed-valence lanthanum manganites during the past decade, were analyzed by x-ray photoemission spectroscopy with respect to their manganese valence under photoexcitation. The comparative analysis of the Mn 3s exchange splitting of La$_{0.7}$Ce$_{0.3}$MnO$_3$ (LCeMO) films in the dark and under illumination clearly shows that both oxygen reduction and illumination are able to decrease the Mn valence towards a mixed 2$+$/3$+$ state, independently of the film thickness and the degree of CeO$_2$ segregation. Charge injection from the photoconductive SrTiO$_3$ substrate into the Mn e$_g$ band with carrier lifetimes in the range of tens of seconds and intrinsic generation of electron-hole pairs within the films are discussed as two possible sources of the Mn valence shift and the subsequent electron doping.
%U http://arxiv.org/abs/1310.4937v2