Effect of annealing conditions on structural and luminescencent properties of Eu3+-doped Gd2Ti2O7 thin films

Antić, Željka; Prashanthi, K.; Ćulubrk, Sanja; Vuković, Katarina; Dramićanin, Miroslav D.; Thundat, Thomas

doi:10.1016/j.apsusc.2015.12.137

Cited by 11 publications

(9 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Recently, Antić et al, also reported increase in the crystallite size of Eu 3+ -doped Gd 2 Ti 2 O 7 thin films on high temperature anealing. [31] It may be noted that the crystallite size calcuated from the XRD is smaller than grain size measured from the SEM. This is because grains are composed of more than one crystallite.The calculated value of the micro-strain in the as-sintered sample is 0.24 %; whereas its value are 0.09%, 0.11%, 0.13% for the samples anealed at 1300 o C,1400 o C, and 1500 o C, respectively.…”

Section: Resultsmentioning

confidence: 89%

Influence of grain growth on the structural properties of the nanocrystalline Gd2Ti2O7

Kulriya

Yao

Scott

et al. 2017

Journal of Nuclear Materials

View full text Add to dashboard Cite

The microstructure evolution and grain growth kinetics of the nanocrystalline Gd 2 Ti 2 O 7 drastically affect its properties and functionalities as thermal barrier coatings and nuclear waste forms for actinide incorporation. Here, we report the synthesis of the dense nano-sized Gd 2 Ti 2 O 7 by high energy ball milling (HEBM), and spark plasma sintering (SPS), and also investigated the isothermally annealing induced grain coarsening and structural properties variations. Asprepared nano powder (D~60 nm) by HEBM exhibited an amorphous nature, which was consolidated to a dense single phase crystalline pyrochlore nano-ceramic (D~120±10 nm) by SPS sintering at 1200 o C. Isothermal annealing was performed at different temperatures (1300 o C-1500 o C) with holding time varying from 0.5 to 8 hours, and the pyrochlore phase is stable with no indication of a transformation into a defect fluorite structure. A rapid initial grain growth was observed which increased with temperature and annealing durations due to the large drive force of the curvature-driven grain coarsening of the nano-ceramics, and grain growth saturates at longer durations. The calculated value of the time constant and activation energy for the nanocrystalline Gd 2 Ti 2 O 7 were 0.52±0.02 and 240±20 kJ/mol (~2.48 eV), respectively. The enhanced grain growth kinetics with a lower value of activation energy can be explained by the effect of fast diffusion across the grain boundaries for dense nanoceramics.

show abstract

Section: Resultsmentioning

confidence: 89%

Influence of grain growth on the structural properties of the nanocrystalline Gd2Ti2O7

Kulriya

Yao

Scott

et al. 2017

Journal of Nuclear Materials

View full text Add to dashboard Cite

show abstract

“…The doping level of each phosphor was at 15 mol%, which was the optimal doping in Gd 2 Ti 2 O 7 :Eu 3+ phosphors . To avoid possible moisture, Eu 2 O 3 and Gd 2 O 3 were preheated at 1000°C for 2 hours before weighing.…”

Section: Methodsmentioning

confidence: 99%

“…For example, Gd 2 Ti 2 O 7 has gained considerable attention in modern solid‐state sciences, such as ferrimagnetism, semiconductor, photocatalyst, fast ion conductors, resistors, sensors and phosphors. In particular, Eu 3+ ‐doped Gd 2 Ti 2 O 7 nanoparticles and thin films have been developed as efficient phosphors. Gd 2 Ti 2 O 7 :Eu 3+ presents a potential application as a probe for luminescence thermometry and ionic conductivity .…”

Section: Introductionmentioning

confidence: 99%

“…Second, microstructures of Eu 3+ ions can greatly influence the emission transitions of 5 D 0 – 7 F 2 (electric dipole) and 5 D 0 – 7 F 1 (magnetic dipole) . Eu 3+ ‐doped Gd 2 Ti 2 O 7 exhibits a typical yellow‐red luminescence color because of its cubic‐type host with the center of symmetry ( D 3d ) of Gd 3+ ions . Consequently, the cation substitution produces a tunable color of Eu 3+ by adjusting the symmetry in Gd 2 Ti 2 O 7 .…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Efficient red‐emitting phosphor of Eu³⁺‐activated (Na_0.5Gd_1.5)(TiSb)O₇ derived via cation‐substitutions in Gd‐Pyrochlore

et al. 2018

View full text Add to dashboard Cite

Rare‐earth (RE) titanate pyrochlore with perovskite‐layered structure is a well‐known engineering material in applied in many field. In this work, a red‐emitting phosphor of Gd2−xNaxTi2−2xSb2xO7:Eu3+ (x = 0‐0.5) was developed via cation substitutions of (Sb5+→Ti4+) and (Na+→Gd3+) in Gd2Ti2O7. The motivation is based on the fact that the introduction of cation‐disorders has been regarded to be an effective approach for improving the luminescent efficiency and thermal stability of RE‐activated materials. All the samples were synthesized via facile solid‐state reaction method. The morphology properties were measured via SEM and EDS measurements. The structural Rietveld refinement was performed to investigate the microstructure in pyrochlore lattices. The luminescence properties of Gd2−xNaxTi2−2xSb2xO7:0.15Eu3+ (x = 0‐0.5) has a strict dependence on the cation substitution levels. The band energy of Gd2Ti2O7 is 2.9 eV with a direct transition nature. The incorporation of Sb5+ and Na+ in the lattices moves the optical absorption to a longer wavelength. The cation disorder results in significant improvements of luminescence intensity, excitation efficiency in the blue region, longer emission lifetime and thermal stability.

show abstract

“…Fig. 6b displays a typical PLE spectrum for the emission wavelength of 589 nm and it exhibits several characteristics emission lines at 363, 424, 456 and 527 nm corresponding to the quantum states of 5 D4, 5 D3, 5 D2 and 5 D1, respectively and these states indicate the presence of unintentional dopant Eu 3+ ions in the lattice [7,9,25] . Thus, the PL emission lines at 579, 589 and 613 nm are assigned to spin forbidden f-f transitions associated with 5 D0  7 FJ (J=0,1 and 2) states, respectively.…”

Section: As-grown 20 H 30 H 50 Hmentioning

confidence: 99%

Raman and Photoluminescence Spectroscopic Studies on Structural Disorder in Oxygen Deficient Gd₂Ti₂O_7‐δ Single Crystals

Suganya

Ganesan

Vijayakumar

et al. 2022

Crystal Research and Technology

View full text Add to dashboard Cite

We report on Raman and photoluminescence spectroscopic studies on oxygen vacancy induced structural disorder in Gd2Ti2O7- single crystals grown by optical floating zone technique under argon atmosphere. The oxygen vacancies in Gd2Ti2O7- wafers decrease with thermal annealing in air atmosphere. The full width at half maximum of X-ray diffraction rocking curve decreases from 245 to 157 arc-second and the optical transmittance increases from 23 to 87 % (at 1000 nm) upon post growth thermal annealing. Raman spectroscopic studies reveal a monotonic increase in intensity of O-Gd-O (Eg) and Ti-O (A1g) stretching modes with thermal annealing.Since these modes are associated with modulation of oxygen x parameter which is sensitive to Ti-O octahedron distortion, the increase in Raman intensity indicates an improvement in structural ordering of oxygen sub-lattice in Gd2Ti2O7-. Moreover, the photoluminescence studies also corroborate the Raman analysis in terms of reduction of structural defects associated with oxygen vacancies as a function of thermal annealing. This study demonstrates the effectiveness of using Raman spectroscopy to probe the structural disorder in Gd2Ti2O7- crystals.

show abstract

Effect of annealing conditions on structural and luminescencent properties of Eu3+-doped Gd2Ti2O7 thin films

Cited by 11 publications

References 21 publications

Influence of grain growth on the structural properties of the nanocrystalline Gd2Ti2O7

Influence of grain growth on the structural properties of the nanocrystalline Gd2Ti2O7

Efficient red‐emitting phosphor of Eu³⁺‐activated (Na_0.5Gd_1.5)(TiSb)O₇ derived via cation‐substitutions in Gd‐Pyrochlore

Raman and Photoluminescence Spectroscopic Studies on Structural Disorder in Oxygen Deficient Gd₂Ti₂O_7‐δ Single Crystals

Contact Info

Product

Resources

About

Effect of annealing conditions on structural and luminescencent properties of Eu3+-doped Gd2Ti2O7 thin films

Cited by 11 publications

References 21 publications

Influence of grain growth on the structural properties of the nanocrystalline Gd2Ti2O7

Influence of grain growth on the structural properties of the nanocrystalline Gd2Ti2O7

Efficient red‐emitting phosphor of Eu3+‐activated (Na0.5Gd1.5)(TiSb)O7 derived via cation‐substitutions in Gd‐Pyrochlore

Raman and Photoluminescence Spectroscopic Studies on Structural Disorder in Oxygen Deficient Gd2Ti2O7‐δ Single Crystals

Contact Info

Product

Resources

About

Efficient red‐emitting phosphor of Eu³⁺‐activated (Na_0.5Gd_1.5)(TiSb)O₇ derived via cation‐substitutions in Gd‐Pyrochlore

Raman and Photoluminescence Spectroscopic Studies on Structural Disorder in Oxygen Deficient Gd₂Ti₂O_7‐δ Single Crystals