Speciation of uranium ion in BaHfO₃ perovskite lattice using time resolved fluorescence

The spectra of Actinides are similar to those of lanthanides but are more complicated because of the various reasons. These includes Russell–Saunders coupling scheme is inefficient in heavier actinides, 5^f' electrons have greater penetrating effect and come closer to the nucleus and improper shielding of 5^f' electrons from the surrounding chemical environment leads to ligands effects. Since 5^f', 6^d' and 7^s' electrons have comparable energies, the electronic configuration of the element in a given oxidation state in solution depends on the ligand. This property is known as ligand effect. This is not shown by lanthanides. The f—f transitions in actinides are about 10 times more intense and the ligand field effect is about 2 to 5 times stronger than in other lanthanides