M. Houzet et al., Decoupling of superconducting layers in the magnetic superconductor RuSr2GdCu2O8 - art. no. 184501, PHYS REV B, 6418(18), 2001, pp. 4501
We propose the model for magnetic properties of the magnetic superconductor
RuSr2GdCu2O8, that incorporates the theory of the superconducting/ferromag
netic multilayers. The transition line T-d(h), on which the Josephson coupl
ed superconducting planes are decoupled, i.e., j(c)(T-d) = 0. is calculated
as a function of the exchange energy h. As the result of this decoupling a
nonmonotonic behavior of magnetic properties. such as the lower critical f
ield H-c1, Josephson plasma frequency, etc., is realized near (or by crossi
ng) the Td(h) line. The obtained results are used in analyzing the newly di
scovered anti ferromagnetic ruthenocuprate RuSr2GdCu2O8 with possible weak
ferromagnetic order in the RuO2 planes.