Comparison of the Intensities of Chemical and Physical Processes Occurring during Laser-Induced Breakdown of Colloidal Solutions of Tb Nanoparticles with Different Oxidation States

A technique for synthesizing Tb nanoparticles using laser ablation in various liquid media (MQ water, ethanol, isopropyl alcohol, and isobutanol) is considered with the aim of preparing colloidal solutions of Tb nanoparticles, containing different amounts of oxidized particles. The synthesis of nanoparticles in isobutyl alcohol exhibits the lowest percentage of oxidized particles relative to the total number of particles in the resulting colloid, with a final ratio of oxidized Tb₂O₃ particles to all particles close to 5%. The influence of oxidized particles on the intensity of physicochemical processes (formation of plasma, shock waves, acoustic signals, and chemical products as a result of dissociation of water molecules) occurring during optical breakdown of colloidal solutions, has been investigated. The general tendency of the influence of oxidized particles consists in an increase in the intensity of the aforementioned characteristics upon laser breakdown with an increase in the Tb₂O₃ fraction with respect to the total number of particles in the colloid. The observed effect is presumably related to the high aggregability of Tb₂O₃ particles, while the absorption coefficient of particles is of minor importance.