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High-resolution spectroscopy of LaAlO3-Pr3+ pseudo-cubic perovskite single crystals: Crystal-field parameters, hyperfine and deformation splittings.
- Source :
-
Optical Materials . Aug2024, Vol. 154, pN.PAG-N.PAG. 1p. - Publication Year :
- 2024
-
Abstract
- We report high-resolution measurements and analysis of the optical transmission and emission spectra of a concentration series of La (1- x) Pr x AlO 3 (x = 10−3, 9 ⋅ 10−3, and 2 ⋅ 10−2) single crystals in a wide frequency range ((2-27) ⋅ 103 cm−1) at temperatures 5–300 K, below the structural phase transition from the cubic P m 3 ‾ m to the rhombohedral R 3 ‾ c phase. Pr3+ ions substitute for La3+ ions at sites with point symmetry D 3. All recorded spectral lines are assigned to specific initial and final crystal-field (CF) energy levels, the scheme of CF levels is constructed and described by an appropriate set of CF parameters. The structural phase transition is accompanied by shear strains and the formation of ferroelastic twin domains of four types compressed along one of the four C 3 axes in the parent cubic crystal lattice. Specific features of the measured spectra, namely, anomalous broadening of spectral lines and doublet structure of some lines corresponding to transitions between CF singlets and doublets, are considered as a result of interaction of 4 f electrons with the field of random shear deformations competing at the boundaries of twin domains. Modeling of the observed line shapes was performed taking into account both hyperfine interactions and random lattice strains, as well as the effect of temperature. The width (6.6 ± 0.7)⋅10− 4 of the introduced two-dimensional distribution function of random strains was found from a comparison of simulated and measured profiles of the split spectral lines. The results of this work can be applied for quantitative assessment of crystal quality. • High-resolution absorption and luminescence spectra of LaAlO 3 :Pr3+ were obtained. • Сrystal-field parameters for Pr3+ in LaAlO 3 were found based on spectra analysis. • Boundaries of ferroelastic twin domains are a source of random lattice strains. • Shape of spectral lines is modeled considering hyperfine structure and random strains. • Modeling takes into account the effect of temperature on the line shape. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 09253467
- Volume :
- 154
- Database :
- Academic Search Index
- Journal :
- Optical Materials
- Publication Type :
- Academic Journal
- Accession number :
- 178537550
- Full Text :
- https://doi.org/10.1016/j.optmat.2024.115629