2011/03/12 by Sina Zapf, Zapf, Sina, Dan Wu +9
Physics and Astronomy · #FOS: Physical sciences #Superconductivity (cond-mat.supr-con) #cond-mat.supr-con
paper · pdf · doi:10.48550/arxiv.1103.2446
4 pages, 4 figures
arxiv created 2011/03/12 · arxiv updated 2011/03/15
Among iron 122 pnictide superconductors, the EuFe2As2 series draws particular interest because, in addition to superconductivity or the long-range spin-density-wave order in the Fe subsystem, the localized Eu2+ magnetic moments order at low temperatures. Here we present a novel scheme of how the spins align in the Eu compounds when pressure varies the coupling; we explain magnetization measurements on EuFe2(As1-xPx)2 single crystals as well as other observations of the Eu2+ ordering previously reported in literature. The magnetic moments of the Eu2+ ions are slightly canted even in the parent compound EuFe2As2, yielding a ferromagnetic contribution along the c-direction that becomes stronger with pressure. Reducing the interlayer distance even further, the antiferromagnetic coupling of the ab planes finally turns ferromagnetic.