Atomic ordering in FeSr2LnCu2O6+ system (Ln=Nd, Y and Er)

Fe ion distribution and superconductivity ofFeSr2RECu2O6+yHata1, Yamaugchi2, Kinoshita3 et al. 2014Physica C: Superconductivity and its Applications3120View full textAdd to dashboardCite

“…As stated earlier, no tetragonal-to-orthorhombic transition occurred in this compound during N 2 annealing. In addition, it was previously found that the relative amount of Fe ions at Cu(2) sites was twice as large as that for YFe1212, and mutual substitution of Sr and Nd ions occurred [12]. This disorder to the crystal structure may be the cause of the broad Mössbauer absorption spectrum.…”

“…The diffraction peaks were indexed and the lattice constants were refined by the integrated X-ray powder diffraction software, PDXL2 [11] on the basis of a Ba 2 YCu 3 O 6 -type structure model [9] and a CoSr 2 YCu 2 O y -type superstructure model [12,13].…”

Metal-to-Insulating Transition in the Perovskite System YSr2Cu2FeO8−δ(0 < δ < 1) Modeled by DFT Methods

“…Importantly, the results indicate that corrugation of the [FeO 4 ] tetrahedral units and their relative orientation along the stacking direction originate an additional superstructure with a diagonal orthorhombic unit cell of dimensions √2 a p × 6 a p × √2 a p in the Imma space group (note the change of S.G. setting as described in Table ). Therefore, the refined crystal structure of YSr 2 Cu 2 FeO 7.08 is in close agreement with the one reported by Mochiku et al (ICSD file 151653) for the YSr 2 Cu 2 FeO 7.11 compound . The crystallographic model with the Imma space group accounts for the presence of two types of tetrahedral chains in the Fe layers, which are left- and right-hand rotated.…”

Structure phase transition in FeSr2YCu2O6+δ

“…Therefore, these indicate that the transformation begins from the FeO 6 octahedron to the FeO 4 tetrahedron since the oxygen deficiency in the FeO 6 octahedron increases with increasing temperature. The electron diffraction study [17,18] shows that the streaks due to the incomplete arrangement of the FeO 4 tetrahedron were observed in the tetragonal N 2 -annealed FeSr 2 YCu 2 O 6+d . There is a possibility that the arrangement of the FeO 4 tetrahedron occurs locally.…”

“…The crystal structure of FeSr 2 YCu 2 O 6+d was refined using the Rietveld analysis program RIETAN-TN [14] on the basis of the tetragonal Ba 2 YCu 3 O 6+d -type structure model (space group P4/mmm) [15] and the orthorhombic CoSr 2 YCu 2 O 7 -type structure model (space group Ima2) [16,17]. The crystal structures are shown in Fig.…”