Study of the dependence of the magnetic moment of La _1−x Sr _x MnO ₃ on the Sr doping level x

Abstract

The dependence of the magnetic moment of the perovskite manganites La1−xSrxMnO3 on the Sr doping level, x, is fitted using an oxygen 2p itinerant electron model for magnetic oxides (i.e., the IEO model), which is similar to the O 2p hole model proposed by Alexandrov et al. (Phys. Rev. Lett., 96 (2006) 117003). According to this IEO model, the itinerant electrons in these manganites are oxygen 2p electrons (or 2p holes) rather than 3d electrons, as assumed in the double-exchange interaction model. Furthermore, the proposed IEO model describes the process by which the itinerant electrons transit along the O2−–Mn2+–O2−–Mn3+–O1− ion chains in La1−xSrxMnO3 (x < 0.15), wherein a 2p hole is present in the outer orbit of the O1− anion and the magnetic moment of the Mn3+ cation is opposite to that of the Mn2+ cation.