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Abstract:

We have investigated the orbital and magnetic correlations of the manganese sub-lattice in the archetypical half-doped manganite La 0.5Sr 1.5MnO 4 using the enhanced sensitivity of resonant soft x-ray diffraction at the Mn L edges. We have separately measured the energy dependence of the scattered intensity from both the (1/4, 1/4, 0) and (1/4,1/4,1/2) reflections indicative of the long-range correlations of orbital and magnetic order respectively. Measurements of the integrated intensity of the different features in the resonant energy spectrum show the different origins of the orbital correlations and their variation with temperature. The results also give evidence for a strong coupling between the orbital and spin degrees of freedom. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.

Abstract:

We report the growth of single crystals of La1- xSrxCoO3+δ (x=0.0 and 0.33) by the floating-zone technique in an image furnace under high pressure (7-9 atm). Single crystals of diameter 10 mm and length 100 mm have been obtained. The phase purity, composition, oxygen stochiometry and quality of the crystals were analysed. We discuss the effect on the crystal growth of the growth atmosphere. We also present some of the magnetization data for the grown crystals. © 2004 Elsevier B.V. All rights reserved.