Abstract

Ni²⁺ is a rare example of a 3d transition metal ion (TM) that possesses more than one metastable emitting state. The only other 3d TM for which higher-excited state emission has been reasonably well characterized is Ti²⁺ (in MgCl2).[1] The presence of a higher-energy (i.e., higher than the first excited state) emitting level provides an experimental handle with which processes between excited states can be explored; processes that would otherwise be inaccessible to study using normal spectroscopic techniques.[2,3]

© 1990 Optical Society of America