Magnetic properties of ${\mathrm{La}}_2$${\mathrm{Cu}}_{1\mathrm{-}\mathit{x}}$${\mathit{M}}_{\mathit{x}}$${\mathrm{O}}_4$ with M=Zn and Ni

The temperature (1.8≤T≤400 K) and concentration (0≤x≤0.10) dependence of the magnetization and magnetic susceptibility of ${\mathrm{La}}_2$ ${\mathrm{Cu}}_{1\mathrm{-}\mathit{x}}$ ${\mathit{M}}_{\mathit{x}}$ ${\mathrm{O}}_4$ with M=Zn and Ni have been measured. The results are compared with the recent measurements of the concentration (0≤x≤0.10) dependence of the muon spin rotation of ${\mathrm{La}}_2$ ${\mathrm{Cu}}_{1\mathrm{-}\mathit{x}}$ ${\mathrm{Zn}}_{\mathit{x}}$ ${\mathrm{O}}_4$. The antiferromagnetic order present in ${\mathrm{La}}_2$ ${\mathrm{CuO}}_4$, which is very sensitive to the introduction of impurities which create mobile holes (such as Sr substitution of the La site), is much less sensitive to impurities which do not create mobile holes in the ${\mathrm{CuO}}_2$ planes. The Ne´el temperature ${\mathit{T}}_{\mathit{N}}$ is depressed rapidly with Zn doping and the width of the peak in the susceptibility increases with x, and thus the peak becomes less well defined. The depression of ${\mathit{T}}_{\mathit{N}}$ in Ni-doped ${\mathrm{La}}_2$ ${\mathrm{CuO}}_4$ and the increase in the width of the susceptibility peak are less rapid compared to those in the Zn-doped material. We also study the influence of doping on the metamagnetic behavior which is concomitant with the antiferromagnetism in these systems.