Premium
Elastic and thermodynamic properties of cerium‐doped yttrium aluminum garnets
Author(s) -
Goncharov Vitaliy G.,
Wei Nian,
Lau Miu Lun,
Ennaceur Sue M.,
Migliori Albert,
Xu Hongwu,
Long Min,
Guo Xiaofeng
Publication year - 2021
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.17679
Subject(s) - yttrium , materials science , dopant , elastic modulus , cerium , resonant ultrasound spectroscopy , debye model , doping , luminescence , analytical chemistry (journal) , softening , mineralogy , thermodynamics , composite material , chemistry , metallurgy , physics , optoelectronics , chromatography , oxide
Cerium‐doped yttrium aluminum garnets (Y 3‐ x Ce x Al 5 O 12 , Ce:YAGs) are promising yellow light‐emitting components of solid‐state white light‐emitting diodes. Although there have been numerous studies examining the effects of Ce concentrations on the luminescent properties of Y 3‐ x Ce x Al 5 O 12, the impacts of Ce dopant on the elastic and thermodynamic properties are not well understood. In this work, we used resonant ultrasound spectroscopy (RUS) to determine the effects of Ce doping (0.025, 0.1, 1 at. %) on the elastic and thermodynamic properties of Y 3‐ x Ce x Al 5 O 12 . The elastic moduli calculated via the Voigt–Reuss–Hill (VRH) method demonstrated that low Ce dopant concentrations (≤0.1 at. %) induced negligible effects on the elasticity of the YAG host matrix, while a high Ce concentration (1 at. %) yielded significant softening. RUS spectral analysis and SEM images suggested that the elastic softening originated from microstructural differences induced at higher Ce dopant concentrations. In addition, we demonstrated an increase in elastic anisotropy at higher Ce concentrations, which further elucidated the correlations between structure and elasticity of Y 3‐ x Ce x Al 5 O 12 . Debye temperatures ( θ D ), heat capacities ( C p ), and thermal conductivities ( κ ) were calculated for Ce:YAGs through the relations of RUS‐derived parameters (sound velocities, elastic moduli) and previously determined thermal expansion coefficients. Ce:YAG was found to have a significant reduction in θ D , C p , and κ at Ce concentrations ≥1 at. %. Lastly, extrapolation of C p and κ to higher temperatures allowed the modeling of thermal stress experienced by Y 3‐ x Ce x Al 5 O 12 disks up to 1073.15 K.