Magnetic ordering in the superconducting weak ferromagnetsRuSr2GdCu2O<

RuthenocupratesRuSr2(Eu,Ce)2Živković1, Hirai2, Frazer3 et al. 2002Phys. Rev. B619351View full textAdd to dashboardCite

“…A weak ferromagnetism originates from canting of the Ru moments 3 . The canting arises from the Dzyaloshinsky-Moriya 31 antisymmetric superexchange interaction which, by symmetry, follows from the fact that the RuO 6 octahedra tilt away from the crystallographic c direction; there is still a controversy as to whether the tilting around the axis perpendicular to the c-axis is actually observed 9,30,32 . In Ru-1212 samples containing magnetic (Gd) ions, the dipolar field of the in-plane ferromagnetic components induces an additional ferromagnetic component 7,30 .…”

“…The canting arises from the Dzyaloshinsky-Moriya 31 antisymmetric superexchange interaction which, by symmetry, follows from the fact that the RuO 6 octahedra tilt away from the crystallographic c direction; there is still a controversy as to whether the tilting around the axis perpendicular to the c-axis is actually observed 9,30,32 . In Ru-1212 samples containing magnetic (Gd) ions, the dipolar field of the in-plane ferromagnetic components induces an additional ferromagnetic component 7,30 . Very recently, results of a structural investigation of the Ru-1222 compound (x=1.0) indicates that there are no important differences in rotation or tilting angles between the Ru-1212 and Ru-1222 (x=1.0) compounds 9 , in spite of Ru-1212 exhibiting dominant antiferromagnetic and Ru-1222 dominant ferromagnetic spontaneous magnetic order.…”

“…We start with the generally accepted model for the magnetic structure of the more thoroughly investigated, and simpler, Ru-1212. It is well established 6,30 that the dominant magnetic order is a G-type antiferromagnetic structure in which the Ru moments are aligned antiparallel in all crystallographic directions. The details of the magnetic order, and the stability of a particular ground state 8 can be interpreted only by explicitly including rotations and tilting of the RuO 6 octahedra and considering the orientation of the magnetic moments.…”

Magnetoresistance hysteresis and critical current density in granularRuSr2Gd2−xFelner1, Galstyan2, Lorenz3 et al. 2003Phys. Rev. B5412230View full textAdd to dashboardCite

“…In contrast to the Ru-1212 system in which the antiferomagnetic nature of the Ru sublattice has been determined by neutron diffraction studies, 12,13 the published data up to now have not include any determination of the magnetic structure in Ru-1222. The accumulated results are compatible with two alternative scenarios, both of which are used in understanding the qualitative features at low applied fields.…”

Mössbauer study of the (Ru1-xFex)Sr2GdCu2O8-δ system and two of its possible impurities: SrRuO3 and Gd2CuO4

“…However, by means of neutron diffraction experiments, it has been shown that the dominant magnetic interactions present in RuSr 2 (RE)Cu 2 O 8 are of the antiferromagnetic (AFM) type, with the Ru magnetic moments forming the G-type AFM structure [8][9]. Two schemes have been put forward to explain the observed ferromagnetism: (a) It has been suggested that the Ru magnetic moments tilt in such a way as to give a net magnetic moment perpendicular to the c-axis [10] and (b) a ferrimagnetic ordering of different magnetic moments of the Ru atoms due to a mixed 4+/5+ valence state [11].…”