Detection of magnetism in heavily overdoped La$_{2-x}$Sr$_{x}$CuO$_{4}$ single crystals

We have measured the DC magnetic susceptibility of a heavily overdoped La$_{1.67}$Sr$_{0.33}$CuO$_{4}$ single crystal. In contrast to lower-doped superconducting samples no magnetic anisotropy is observed. However, as previously seen in the normal state, there is a Curie-like term that appears in the susceptibility for strontium content in excess of x$\sim $0.19. This is true even for La$_{1.67}$Sr$_{0.33}$CuO$_{4}$, in which the electronic system is fairly well established to be a Fermi liquid. A tentative explanation of the DC magnetic susceptibility and complimentary MuSR measurements on the same La$_{1.67}$Sr$_{0.33}$CuO$_{4}$ sample is discussed in terms of recent predictions of ferromagnetism in the heavily overdoped regime.