M. v. Zimmermann

Interplay between Charge, Orbital, and Magnetic Order in Pr{sub 1-x}Ca{sub x}MnO{sub 3}

We report resonant x-ray scattering studies of charge and orbital order in Pr{sub 1-x}Ca {sub x}MnO{sub 3} with x=0.4 and 0.5. Below the ordering temperature, T{sub O}=245 K , the charge and orbital order intensities follow the same temperature dependence, including an increase at the antiferromagnetic ordering temperature, T{sub N} . High resolution measurements reveal, however, that long range orbital order is never achieved. Rather, an orbital domain state is formed. Above T{sub O} , the charge order fluctuations are more highly correlated than the orbital fluctuations. We conclude that the charge order drives the orbital order at the transition. (c) 1999 The American Physical Society.

Spin dynamics and orbital state in LaTiO3

A neutron scattering study of the Mott-Hubbard insulator LaTiO3 ( T(N) = 132 K) reveals a spin wave spectrum that is well described by a nearest-neighbor superexchange constant J = 15.5 meV and a small Dzyaloshinskii-Moriya interaction ( D = 1.1 meV). The nearly isotropic spin wave spectrum is surprising in view of the absence of a static Jahn-Teller distortion that could quench the orbital angular momentum, and it may indicate strong orbital fluctuations. A resonant x-ray scattering study has uncovered no evidence of orbital order in LaTiO3.

X-ray resonant scattering studies of orbital and charge ordering in Pr 1 − x Ca x MnO 3

We present the results of a systematic x-ray scattering study of the charge and orbital ordering in the manganite series

Spontaneous symmetry breaking by charge stripes in the high pressure phase of superconducting La1.875Ba0.125CuO4.

{\mathrm{Pr}}_{1\ensuremath{-}x}{\mathrm{Ca}}_{x}{\mathrm{MnO}}_{3}

X-Ray anomalous scattering study of a charge-ordered state in NaV2O5

with

RESONANT X-RAY DIFFRACTION OF THE MAGNETORESISTANT PEROVSKITE PR0.6CA0.4MNO3

x=0.25,

Correlated polarons in dissimilar perovskite manganites

0.4, and 0.5. The temperature dependence of the scattering at the charge and orbital wavevectors, and of the lattice constants, was characterized throughout the ordered phase of each sample. It was found that the charge- and orbital-order wavevectors are commensurate with the lattice, in striking contrast to the results of electron and neutron diffraction studies of samples with

Pressure dependence of the charge density wave in 1T-TaS2 and its relation to superconductivity

x=0.5.

Enhanced charge stripe order of superconducting La2 and #8722;xBaxCuO4 in a magnetic field

High-momentum-transfer resolution studies of the

Field-induced magnetic phases and electric polarization in LiNiPO4

x=0.4