Abstract
The interplay between charge, spin and orbital degrees of freedom in transition metal
oxides has been a matter of much interest in recent years. In this paper we present
X-ray scattering results of charge and orbital ordering in the electron doped
manganite Bi0.24Ca0.76MnO3. Using High Energy
X-ray Scattering (HEXS) the charge ordering, structural modulation due to the
Jahn–Teller ordering and the harmonic of the structural modulation have been
measured. The superlattice reflections due to the Jahn–Teller ordering are found to
maximise in intensity at the Neél point. We have confirmed using resonant
X-ray scattering at the K-edge of manganese and the Anisotropic
Tensor of Susceptibility technique (ATS) that superlattice reflections occurring at a
modulation wavevector of (0.5, 0, 0) are due to charge ordering in a
Mn3+/Mn4+ ordering pattern. In addition superlattice
reflections corresponding to the orbital order were measured at a modulation wavevector of
(0.25, 0, 0). The temperature dependence of both the Jahn–Teller structural
distortion peak (1.75, 2, 0) and the charge ordering peak (3 0 0) were observed to
behave identically, gradually increasing with decreasing temperature.