The influence of Cu substitution for Ru on the magnetic behaviour of a weak ferromagnet, Ca3LiRuO6

The influences of gradual Cu substitution for Ru on the magnetic characteri stics of a weak ferromagnet, Ca3LiRuO6 (with a magnetic ordering temperatur e of 113 K), are reported as obtained by magnetization studies. We find tha t single-phase compounds could be formed only until x = 0.3 in Ca3LiRu1-xCu xO6. We do not find evidence for superconductivity in the temperature range of the investigation (2-300 K). The onset of magnetic ordering is depresse d only marginally with Cu substitution (to about 90 K for n = 0.3), which i ndicates that the magnetic interaction along the chain is not predominantly of a long-range type, but rather of a short-range (superexchange?) type. T here are notable changes in the magnetic field/temperature dependence of th e magnetization, as if there are dramatic changes in the magnetic structure .