X-RAY-SCATTERING STUDY OF CHARGE SCATTERING ASSOCIATED WITH STRIPE ORDER IN LA1.775SR0.225NIO4

In this paper we report the first observation of stripe correlations o f holes in hole-doped La2NiO4 by X-ray diffraction. The experiment was performed in Laue geometry at the hard X-ray beamline BW5 at HASYLAB on a crystal of La1.775Sr0.225NiO4 previously studied by neutron diffr action. Temperature dependences of the intensities and wave vectors of the charge-density-modulation peaks were characterized and found to b e in good agreement with the neutron scattering results. Interestingly , weak, temperature-dependent scattering was also observed at position s consistent with nonresonant X-ray magnetic scattering from the spin correlations; however, a definitive determination of its origin remain s lacking.