Synthesis and characterisation of superconducting RuSr2GdCu2O8

Study of interstitial oxygen mobility in RuSr2GdCu2O8 by internal friction

“…Polycrystalline samples of Ru-1212 composition have been synthesized by the solid-state reactions method, using the mixture of high-purity RuO 2 (99.95%), SrCO 3 (99.99%), Gd 2 O 3 (99.99%) and CuO (99.99%), supplied by Sigma-Aldrich Inc., following an already well-established procedure [7,8]. Under these conditions, the nonstoichiometric oxygen content is 0.07(5) [9].…”

SuperconductingRuSr2GdCu2O8Papageorgiou1, Braun2, Herrmannsdörfer3 2002Phys. Rev. B173170View full textAdd to dashboardCite

“…Klamut et al 29 have tentatively attributed these features to a change of the magnetic ordering of the Ru sublattice upon entering the superconducting state or to an anomalous flux lattice behavior. Artini et al 30 and Bauernfeind 5 report a rather "reversed" effect, where a decrease of the magnetization is observed first, attributed to a Meissner behavior, followed by an increase of the magnetization at lower temperatures. Artini et al 30 attribute the poor visibility of the Meissner state to the existence of a spontaneous vortex state proposed by Bernhard et al 11 or to a phase-lock of an aggregation of small Josephson-coupled superconducting grains or domains proposed by Chen et al 22 .…”

“…Artini et al 30 and Bauernfeind 5 report a rather "reversed" effect, where a decrease of the magnetization is observed first, attributed to a Meissner behavior, followed by an increase of the magnetization at lower temperatures. Artini et al 30 attribute the poor visibility of the Meissner state to the existence of a spontaneous vortex state proposed by Bernhard et al 11 or to a phase-lock of an aggregation of small Josephson-coupled superconducting grains or domains proposed by Chen et al 22 . The field cooled curve of Klamut et al 29 , with an increase of the magnetization just below T c , followed by a plateau at low temperatures is also reminiscent of a "reversed" effect compared to the field cooled curves published by Bernhard et al 11 , which show a decrease of the magnetization just below T c and a plateau at low temperatures, considered as evidence for the existence of a bulk Meissner state in Ru-1212.…”

“…In their paper, Artini et al 30 recognize that the complexity of the magnetic signal of Ru-1212, which consists of contributions from the Gd paramagnetic spin lattice, the Ru spin lattice and the diamagnetic signal due to superconductivity, can drastically affect the quality of a SQUID magnetization measurement, if this is done in a non-uniform field.…”

Variations in structural and physical properties of RuSr2GdCu2O8 samples submitted to annealing and deoxygenation procedures

“…Anyway after many years since their discovery and referring in particular to the phase RuSr 2 GdCu 2 O 8 , object of this work, the coexistence of the two orderings, the type of magnetic ordering, the existence of a single homogeneous or two phases mesoscopically interconnected are still open problems. To go inside the question of the parameters that govern the setup of the two long-range orderings a polycrystalline phase pure master batch of Ru-1212 (AP) was prepared by conventional solid-state reaction [1] and, successively subjected to annealing in flowing O 2 at 1060 C for 1 month (1 M). The sample was then heated in vacuum (p ¼ 4 Â 10 À5 Torr) for 1 h at 600 C (DO) [2].…”