Characterization and crystallization kinetics of Er-doped Li2O–Y2O3–P2O5 glass studied by non-isothermal DSC analysis

This work deals with preparation and characterization of Er-doped lithium–yttrium phosphate glass and study of the influence of the particle size in samples on the crystallization process and its kinetics. Two types of prepared samples were used—powder with particle size fractions 90–106 and 200–212 µm and the bulk one. These glassy samples were studied by non-isothermal DSC measurements at heating rates from 2 to 40 K min−1 under nitrogen atmosphere. Obtained data were used for evaluation of the influence of the particle size on the activation energies of the crystallization process by seven the most widely used methods. Activation energies for both powder and bulk samples calculated by model-free methods (Kissinger, Augis–Bennett, and Matusita–Sakka) were similar and independent on the particle size. On the contrary, the influence of the particle size on the activation energy was well described by isoconversional methods (Kissinger–Akahira–Sunose, Starink, Tang, and Flynn–Wall–Ozawa). Moreover, the prepared glassy samples were calcined at temperature over the crystallization temperature and characterized by powder X-ray diffraction analysis.