Dresden 2003 – wissenschaftliches Programm

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MA: Magnetismus

MA 3: Magnetische Materialien

MA 3.2: Vortrag

Montag, 24. März 2003, 10:30–10:45, HSZ/401

Complementary X-ray and neutron scattering from lightly doped La_1−xSr_xMnO₃ — •Y. Su¹, K. Istomin¹, W. Schweika¹, A. Fattah¹, P. Foucart¹, P. Meuffels¹, D. Wermeille², D. Hupfeld¹, O. Seeck¹, and Th. Brückel¹ — ¹Institut für Festkörperforschung, Forschungszentrum Jülich GmbH, D-52425 Jülich — ²Ames Lab. and Dept. of Phys. and Astr., Iowa State University, Ames IA, U.S.A.

Lightly doped La_1−xSr_xMnO₃ compounds exhibit very intriguing properties due to strong electronic correlations, such as charge/orbital ordering (CO/OO) and colossal magnetoresistance. However, even after some extensive investigations during recent years, controversies concerning the nature of the intriguing ferromagnetic insulating phase (FMI) at low temperature still remain at large. To re-examine the crucial role of the CO/OO in the FMI phase, complementary synchrotron X-ray and neutron scattering experiments have been undertaken on a series of high-quality and well-characterized single crystals of lightly doped La_1−xSr_xMnO₃ (0.1<x<0.17). The complex lattice modulations associated with CO/OO were observed and extensively characterized by high-resolution X-ray scattering. Resonant X-ray scattering measurements were carried out to directly investigate the nature of the charge/orbital ordering. The magnetic correlations in this compound were examined by neutron scattering. In particular, we demonstrated that scattering methods utilizing both polarized neutrons and synchrotron X-ray photons can yield unique information on the electronic correlation in this compound.