Energy transfer and radiationless relaxation processes in Nd3+ and Cr3+ doped mixed garnet crystals

Temperature and pressure dependence of the optical properties of Cr3 +-doped Gd3Ga5O12nanoparticles

“…However, the thermal population of 2 E and 4 T 2 states is governed by the zero phonon line (ZPL) energy separation, E ZPL = E ZPL ( 4 T 2 ) − E ZPL ( 2 E) = 360 cm −1 . This value is similar to those previously reported for the bulk, 300-400 cm −1 [7,8]. The mixed states resulting from the spin-orbit interaction are given by…”

“…For simplicity, the participation of the 2 T 1 state has been neglected in this work, since the 2 T 1 state population decays non-radiatively, and a complete description of the 4 T 2 , 2 E and 2 T 1 state mixing does not change the main conclusions reached taking into account only the emitting states 4 T 2 and 2 E. Oxide garnets are attractive host materials to investigate ESCO processes since they provide intermediate crystal fields around Cr 3+ , which are close to the 4 T 2 -2 E crossing point, resulting in a strong spin-orbit mixing of the excited states [6]. Specifically, the 4 T 2 state in bulk GGG:Cr 3+ has been found to be located approximately 300-400 cm −1 above the 2 E level (figure 1(a)) [7,8].…”