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  Betto, D.; Bluschke, M.; Putzky, D.; Schierle, E.; Amorese, A.; Fürsich, K.; Blanco-Canosa, S.; Christiani, G.; Logvenov, G.; Keimer, B.; Minola, M.: Imprint of charge and oxygen orders on Dy ions in DyBa₂Cu₃O_6+x thin films probed by resonant x-ray scattering. Physical Review B 102 (2020), p. 195149/1-9

10.1103/physrevb.102.195149
Open Access Version

Abstract:
We used resonant x-ray scattering at the Cu L3 and Dy M5 edges to investigate charge order in thin films of underdoped DyBa2Cu3O6+x (DyBCO) epitaxially grown on NdGaO3 (110) substrates. The films show an orthorhombic crystal structure with short-range ortho-II oxygen order in the charge-reservoir layers. At the Dy M5 edge we observe diffraction peaks with the same planar wave vectors as those of the two-dimensional charge density wave in the CuO2 planes and of the ortho-II oxygen order, indicating the formation of induced ordered states on the rare-earth sublattice. The intensity of the resonant diffraction peaks exhibits a nonmonotonic dependence on an external magnetic field. Model calculations on the modulation of the crystalline electric field at the Dy sites by charge and oxygen order capture the salient features of the magnetic field, temperature, and photon energy dependence of the scattering intensity.