Inversion of the relative probabilities of the f-f and f-d transitions in the Ln3+ lanthanide ions at their radio- and sonoexcitation as compared to photoexcitation

Luminescence of Trivalent Lanthanide Ions Excited by Single-Bubble and Multibubble Cavitations

“…This confirms the excitation of Gd 3+ under US (although the QY and consequently the excitation mechanism cannot be determined) and its significant quenching. The origin of the line reported by Sharipov et al remains unknown.…”

“…5 The second excitation pathway is by collisions with the "hot" particles generated during bubble collapse, 6 similarly to what happens under α-, β-, or X-ray irradiation. 7 In radiation chemistry, the impact generates excited water molecules that then transfer their energy to the lanthanide ions; alternatively, excited ions can also be produced by direct action of the radiation. 8 In sonochemistry, direct excitation by collision and transfer of kinetic and excitation energy from the "hot" particles occurs in the bubble or at its interface.…”

“…The first excitation pathway, sonophotoluminescence (SPL), is by photons emitted by cavitation bubbles at collapse . The second excitation pathway is by collisions with the “hot” particles generated during bubble collapse, similarly to what happens under α-, β-, or X-ray irradiation . In radiation chemistry, the impact generates excited water molecules that then transfer their energy to the lanthanide ions; alternatively, excited ions can also be produced by direct action of the radiation .…”

“…Up to now, only one research group studied lanthanide sonoluminescence, using low-frequency 20 kHz ultrasound and low-resolution spectrometer. ,, Because the ultrasonic frequency is known to control chemical and sonoluminescence activity, it would be of particular interest to compare lanthanide SL at various ultrasonic frequencies. Moreover, a comparison with a single-bubble (SB) system is worth it in the light of some recent works that showed the possibility of collisional excitation in an SB system.…”

New sonochemiluminescence involving solvated electron in Ce(III)/Ce(IV) solutions

“…Previously, the existence of Ce 3+ CE was not observed at studying MBSL of Ce 3+ [14] , [16] . Indeed, the contribution of this mechanism is small due to the low yield of Ce 3+ CE [30] (despite the movement of the bubbles and the deformation injection of the solution under conditions of multibubble sonolysis). Therefore, the contribution of CE is difficult to separate from the contribution of SPL mechanism.…”