Thermal Behavior, Crystallization Kinetics, and Near 2 μm Emission of Tm 3+ Doped TeO 2 ‐BaO‐Nb 2
Tingyang Chen, Di Liu, Zhaojing Kuang, Ying Tian, Liaolin Zhang, Junjie ZhangABSTRACT
In this work, a series of Tm 3+ ‐doped TeO 2 ‐BaO‐Nb 2 O 5 glasses were designed to elucidate the relationship between rare‐earth incorporation, thermal kinetic evolution, crystallization behavior, and near 2 μm emission properties. Differential scanning calorimetry (DSC) combined with kinetic analyses was employed to reveal the concentration‐dependent evolution of glass transition and crystallization kinetics. The apparent activation energies associated with glass transition (E g ) and crystallization (E c ) were evaluated using multiple kinetic models. With increasing Tm 2 O 3 concentration, the mean E g increases from 567.25 to 1080.69 kJ/mol, whereas the mean E c initially increases from 279.09 to 328.85 kJ/mol and subsequently decreases to 204.99 kJ/mol, indicating concentration‐dependent changes in thermal relaxation and crystallization processes. Avrami analysis provided insight into the possible crystallization behavior under the adopted kinetic models and non‐isothermal DSC conditions. XRD of heat‐treated samples supports this mechanism, showing one weak peak indicative of incipient surface crystallization nucleation, as predicted by kinetics. Optical measurements reveal that the glass containing 1.25 mol% Tm 2 O 3 exhibits the strongest 1.8 μm emission and a relatively long fluorescence lifetime of 1.635 ms. These findings provide insights into the design of thermally stable rare‐earth‐doped infrared luminescent glasses with tunable near‐2 μm emission.