Phonon mode and electronic bottleneck associated with the nonradiative relaxation in Ni²⁺-doped MgO

Using the up-converted hot luminescence technique, the measurements performed in Ni²⁺:MgO are reported in order to obtain information on the phonon modes and electronic bottlenecks associated with the nonradiative relaxation of the impurity Ni²⁺ ions. This technique is useful in obtaining information regarding the phonon modes involved in the radiationless relaxation, on electronic bottlenecks, and short-lived electronic states of impurity metal ions in dielectric crystals.