Premium
Sol‐gel route to nanocrystalline Eu 2 Ti 2 O 7 films with tailored structural and optical properties
Author(s) -
Mrázek Jan,
Vytykáčová Soňa,
Buršík Jiří,
Puchý Viktor,
Girman Vladimír,
Peterka Pavel,
Kašík Ivan
Publication year - 2019
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.16524
Subject(s) - nanocrystalline material , materials science , annealing (glass) , nanocrystal , sol gel , refractive index , crystallization , titanate , europium , chemical engineering , nanotechnology , luminescence , optoelectronics , composite material , ceramic , engineering
We present a generic sol‐gel approach for the preparation of highly transparent europium titanate Eu 2 Ti 2 O 7 films with tailored structural and optical properties. The films were prepared by a sol‐gel process and thermally treated in a rapid thermal annealing furnace. We determined the effects of the annealing temperature on structural, morphological, and optical properties of the films. We evaluated film's optical constants. The size of the primary nanocrystals and the film's refractive index were tailored by the annealing temperature. The crystallization of Eu 2 Ti 2 O 7 started at 800°C and the nanocrystals grew with increasing annealing temperature reaching the size from 20 nm to 100 nm. The energy of nanocrystal growth was 21 ± 3 kJ·mol −1 . Increasing nanocrystal size caused the regular growth of the refractive index recorded at 632 nm from 2.07 to 2.17 for the films annealed at 800°C and 1200°C, respectively. These results provide fundamental information about the effects of the structure and the morphology of the films on their optical properties. The presented approach can be extended to other rare earth‐doped titanates and these films can be used as passive protective coatings as well as active materials suitable for photonic and spintronic applications.