Orbital and magnetic ordering in Pr1-xCaxMnO3 and Nd1-xSrxMnO3 manganites near half doping studied by resonant soft x-ray powder diffraction

Here we present resonant soft x-ray diffraction data in the vicinity of the Mn L-2,L-3 edges on R1-xTxMnO3 manganites (R=Pr, Nd and T=Ca, Sr) close to half doping. For Pr0.6Ca0.4MnO3 (PCMO), the energy dependence of the superimposed orbital and magnetic reflections are studied using various incident x-ray polarizations. For Nd0.5Sr0.5MnO3 (NSMO), the energy dependence of the orbital ordering reflection is found to be very similar to that found in other manganites systems. These two results are compared to those presented in the literature on single-crystal samples. Whereas our results are in good agreement with the spectral shape of a superposition of magnetic and orbital signals in PCMO, the magnetic signals are only moderately larger than the orbital signals. The results on NSMO do not agree with previously presented data on single crystals and cast doubt on the proposed occurrence of a double-stripe orbital order.