Electronic properties of beryllides of the rare earth and some actinides

A magnetic study has been conducted of 17 beryllides of the form $M{\mathrm{Be}}_{13}$, $M$ being a rare earth, Th, U, and an alloy ${\mathrm{La}}_{0.75}$ ${\mathrm{Tm}}_{0.25}$. Specific-heat studies were also made for $M=\mathrm{L}\mathrm{a},\mathrm{P}\mathrm{r},\mathrm{S}\mathrm{m},\mathrm{T}\mathrm{m},\mathrm{L}\mathrm{u},\mathrm{T}\mathrm{h},\mathrm{a}\mathrm{n}\mathrm{d}\mathrm{U}$. A thorough crystal-field analysis is presented for Pr${\mathrm{Be}}_{13}$, Tm${\mathrm{Be}}_{13}$, both ions being in a crystal-field singlet ground state, and the expected nuclear cooling and ordering behavior is also thoroughly discussed.