Charge/orbital ordering vs. Jahn-Teller distortion inU. Staub1, V. Scagnoli1, A. M. Mulders1, M. Janousch1, Z. Honda2 and J. M. Tonnerre3
1 Swiss Light Source, Paul Scherrer Institut - 5232 Villigen PSI, Switzerland
2 Department of Functional Materials Science, Saitama University Shimo-Ohkubo 255, Saitama, 338-8570, Japan
3 Laboratoire de Cristallographie, CNRS - 38042 Grenoble, France
received 23 February 2006; accepted in final form 4 October 2006
published online 1 November 2006
Temperature dependences of a magnetic and an orbital Bragg reflection at the Mn L2,3 edges of have been collected. The temperature evolution of the orbital reflection depends strongly on the X-ray energy and reflects the different order parameters, which are assigned to orbitals and Jahn-Teller distortions. The Jahn-Teller order parameter saturates at , whereas the orbital order parameter gradually increases. These results are discussed in context with the possible driving forces, the orbital-orbital super exchange and the Jahn-Teller strain field interaction.
75.25.+z - Spin arrangements in magnetically ordered materials (including neutron and spin-polarized electron studies, synchrotron-source X-ray scattering, etc.).
71.30.+h - Metal-insulator transitions and other electronic transitions.
75.47.Lx - Manganites.
© EDP Sciences 2006