The d- and f-Block Elements

Diamagnetism needs no unpaired $f$ electrons. $\mathrm{C}{\mathrm{e}}^{4+}$ is $4f^0$ and $\mathrm{Y}{\mathrm{b}}^{2+}$ is $4f^{14}$ — both diamagnetic. $\mathrm{C}{\mathrm{e}}^{3+}$ ($f^1$), $\mathrm{E}{\mathrm{u}}^{2+}$/$\mathrm{G}{\mathrm{d}}^{3+}$ ($f^7$), $\mathrm{E}{\mathrm{u}}^{3+}$ ($f^6$), $\mathrm{P}{\mathrm{m}}^{3+}$ ($f^4$), $\mathrm{S}{\mathrm{m}}^{3+}$ ($f^5$) are all paramagnetic.