Negative Magnetisation and Absence of Superconductivity in RFe4Al8(R=Lu, Yb) Compounds

We report researches for superconductivity and the effect of negative magnetisation in the RFe4Al8 (R = Lu, Yb) compounds by means of magnetic measurements and microwave absorption.Contrary to the earlier reports we do not confirm the existence of any traces of superconductivity in these compounds.Instead of the superconductivity and the Meissner effect, the YbFe 4 Al 8 compound exhibits the effect of negative magnetisation, whereas the LuFe 4 Al 8 compound shows an exact antiferromagnetic behaviour.