The ruthenocuprates: natural superconductor–ferromagnet multilayers

Abstract

The recently discovered ruthenocuprates have attracted great interest because of the microscopic coexistence of superconducting and ferromagnetic order. Typically, these materials become magnetically ordered at temperatures around 125-145 K and superconductivity sets in between 15 and 50 K. While superconductivity arises in the CuO2 layers the RuO2 layers in between order magnetically. In this paper we summarize some of the crystallographic, magnetic and superconducting properties of the ruthenocuprates, as obtained from investigations on polycrystalline samples as well as single crystals. RésuméDécouverts récemment, les ruthenocuprates ont suscité un intérêténormeà cause de la coexistence d'un ordre supraconducteur et ferromagnétique. Dans ces matériaux, la phase magnétique apparaît autour de 125-145 K et la phase supraconductrice entre 15 et 50 K. Les couches de CuO2 sont supraconductrices et ce sont les couches interstitielles de RuO2 qui sont ordonnées magnétiquement. Dans cet article nous résumons quelques-unes des propriétés cristallographiques, magnétiques et supraductrices des ruthenocuprates déduites desétudes sur deś echantillons polycristallins ainsi que sur des monocristaux.

Magnetic phase diagram and correlation between metamagnetism and superconductivity in Ru0.9Sr2YCu2.1O7.9

“…21 However, as mentioned in Sect. I, there were many different interpretations 2,14-16 reviewed in Ref.…”

Magnetic Structure ofRuSr2GdCu2O8Determined by Resonant X-Ray Diffraction

“…RuSr 2 GdCu 2 O 8 (Ru1212) and related compounds with alternating RuO 2 and CuO 2 layers have attracted tremendous scientific interest in recent years, mainly due to the microscopic coexistence of long-range magnetic order and superconductivity [1][2][3]. With a magnetic ordering temperature T N ¼ 100-150 K and a superconducting transition temperature of $15-50 K, Ru1212 exhibits not only the highest magnetic transition temperature among all magnetic superconductors, but also the broadest coexistence range of magnetic order and superconductivity.…”

Microwave and magnetotransport properties ofRuSr2RCu2O8(Požek1, Kupčić2, Dulčić3 et al. 2008Phys. Rev. B6100View full textAdd to dashboardCite

“…Despite the intensive investigation of ruthenatecuprates in the last ten years, a lot of questions about the nature of magnetic order and superconductivity, in particular their coexistence, are still unanswered [1]. It is well established that in RuSr 2 RCu 2 O 8 (Ru1212R, R = Eu, Gd, Y) compounds the magnetic ordering of ruthenium sublattice occurs at about 130 K. The ordering is predominantly antiferromagnetic (AFM) with an easy axis perpendicular to the layers and with a weak ferromagnetic (FM) component parallel to the layers.…”