Simulation and demonstration of glass-like heat-transfer equations in rare-earth doped alkaline earth fluoride crystals

The intriguing phenomenon of glass-like heat-transfer behavior in rare-earth (RE) doped alkalineearth fluoride (AEF) systems has captivated researchers' attention in fundamental science. The heat-transfer dynamics of AEF crystals exhibit transitions between crystalline-like and glass-like states as the species and concentration of doped RE ions are altered. Here, the applicability constraints of glassy thermal models in RE-AEF systems are elucidated by optimizing and adjusting parameters within the governing equations. Building upon insights derived from defective phonon-scattering calculations, the diverse factors that influence glass-like heat-transfer behavior in AEF crystals are comprehensively analyzed. The variation mechanism of the thermal conductivity models in RE-AEF crystals is subsequently simulated and explicated, employing an in-depth investigation into the parameters embedded within thermal equations. This endeavor ultimately establishes a solid theoretical foundation for the thermal investigation of disordered crystals.