Systematic study on the crystal structure and properties of RuSr2RCu2O8-delta (R= Gd, Tb, Dy, Y, Ho, Er)

摘要

The coexistence of superconductivity and magnetic order seems to take place in the so-called ruthenate-cuprates (Ru-1212). A systematic study is carried out on crystal structure of the RuSr2RCu2O8-delta phases (R= Gd, Tb, Dy. Y, Ho, Er) synthesized under high pressure by X-ray powder diffraction. RuSr2RCu2O8-delta (R = Gd, Tb, Dy, Y, Ho, Er) has the Ru-1212-type structure of a tetragonal symmetry and the RuO6 octahedra rotate around the c-axis with an additional small rotation around an axis perpendicular to c. The DC-magnetization data establish that compounds with R= Gd, Y, Ho, Er exhibit ferromagnetic order below about 140 K, and the Meissner effect was observed at low temperature for R= Y compound. (C) 2003 Elsevier Inc. All rights reserved.