1304.6900 (A. Caviezel et al.)

Identification of coherent lattice modulations coupled to charge and
orbital order in a manganite    [PDF]

A. Caviezel, S. O. Mariager, S. L. Johnson, E. Möhr-Vorobeva, S. W. Huang, G. Ingold, U. Staub, C. J. Milne, S. -W. Cheong, P. Beaud

We apply grazing-incidence femtosecond x-ray diffraction to investigate the details of the atomic motion connected with a displacively excited coherent optical phonon. We concentrate on the low frequency phonon associated with the charge and orbital order in the mixed valence manganite La0.25Pr0.375Ca0.375MnO3 for T < 210 K. We measure the response of three superlattice reflections that feature different sensitivities to the motion of the unit cell constituents. The results support the assignment to a translational mode of the Mn4+ atoms together with the oxygen atoms connecting adjacent Mn4+ sites.

View original: http://arxiv.org/abs/1304.6900