Optical Phonon Spectra of Lutetium Fluoride, Oxyfluoride,and Lutetium Oxide Nanoparticles

摘要

Nano- and microcrystalline LuF_3phases have been synthesized with particle sizes of 30 nm and30 μm, respectively. Analysis of the IR reflection spectra measured at T = 300 K showed that the nanophasediffers from the microcrystalline phase by reduced optical phonon frequencies. It is established that annealingof the LuF3 nanophase in air leads to the formation of nanoparticles of the LuO_(1-x)F_(1+ 2x)and Lu_2O_3composi-tions. The IR reflection spectra of the nanophases indicate that these nanoparticles consist of an oxyfluoride coresurrounded with a Lu_2O_3shell; the latter is in strained state.