Abstract
Metallic 5f materials have very strong coupling of magnetic moments and electrons mediating electrical conduction. It is caused by strong spin-orbit interaction, coming with high atomic number Z, together with involvement of the 5f states in metallic bonding.
We have used the recently discovered class of uranium (ultra)nanocrystalline hydrides, which are ferromagnets with high ordering temperature, to disentangle the origin of negative temperature coefficient of electrical resistivity. In general, the phenomenon of electrical resistivity decreasing with increasing temperature in metals can have several reasons.
The magnetoresistivity study of these hydrides reveals that quantum effects related to spin-disorder scattering can explain the resistivity behavior of a broad class of actinide compounds.