Strong Orbital Magnetism and Possible Mixed Valence in4dSystems

Tc and Ru ions in alkali-metal hosts exhibit local magnetic $4d$ moments with large orbital contributions which imply small crystal fields and spin-orbit coupling for the $4d^6$ shell of Tc in Rb. Probably we have found mixed valence for a $d$ system. The results for Tc in Rb can be well reproduced by a mixture of the ionic ${\mathrm{Tc}}^{2+}$ and ${\mathrm{Tc}}^{1+}$ levels. The magnetism of Ru in Rb and Cs is consistent with a predominant $4d^7$ state along with spin fluctuations of ∼ ${10}^2$ K. The systems were produced and investigated by the perturbed $\gamma$-ray distribution method following heavy-ion reactions.