CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Longchao Liu,Hailian Liu,Wenqian Zou,Shoujun Ding
Trivalent erbium (Er 3+ ) doped trivalent ytterbium (Yb 3+ ) stoichiometric upconversion (UC) phosphors YbTaO 4 (YbTaO 4 :Er 3+ ) synthesized using the high temperature solid-state reaction method. The phase structure was analyzed using X-ray diffraction (XRD), scanning electron microscope (SEM) and XRD Rietveld refinement methods. The vibration of the bonds was revealed through Fourier transform infrared (FT-IR) spectroscopy. The multi-photon UC green and red luminescence were investigated upon excitation with a 980 nm semiconductor laser , and the critical quenching concentration of Er 3+ in the YbTaO 4 stoichiometric host was derived as high as 15 at.%. The power-dependent UC emission spectra confirmed a two-photon population process for the UC green and red emissions. Furthermore, the temperature-dependent UC emission spectra were measured in the range of 300–570 K, and the optical temperature sensing performance of YbTaO 4 :Er 3+ was demonstrated using the fluorescence intensity ratio (FIR) technique. The maximum absolute sensing sensitivity (S A ) and relative sensing sensitivity (S R ) of YbTaO 4 :Er 3+ were determined as 0.0038 K -1 (@450 K) and 0.0102 K -1 (@300 K), respectively. These results suggest that Er 3+ doped YbTaO 4 stoichiometric phosphors hold great promise as upconversion materials for optical temperature sensing applications.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Coatings
·
2024
·Vol. 14
·期 9
·1097
·
IF 2.9
Jiaxin Liao,Lin Chen,Luyang Zhang,Xunlei Chen,Cheng Xu,Tianyu Li,Jing Feng
Environmental barrier coatings (EBCs) are widely used to protect ceramic matrix composites (CMCs, SiCf/SiC, and Al2O3f/Al2O3), and they should have low thermal expansion coefficients (TECs) matching the CMCs and excellent mechanical properties to prolong their lifetime. Current EBC materials have disadvantages of phase transitions and insufficient mechanical properties, which affect their working temperatures and lifetime. It is necessary to develop new oxide EBCs. Ytterbium tantalate (YbTaO4) is a stable and novel EBC material, and we have improved the mechanical properties and TECs of Yb1−xAlxTaO4(x = 0.05, 0.1, 0.2, 0.3, 0.4, 0.5) ceramics by replacing Yb with Al. XRD, SEM, and EDS are used to verify the crystal and microstructures, and nano-indentation is used to measure the modulus and hardness when changes in TECs are measured within a thermal expansion device. The results show that the phase structure of Yb1−xAlxTaO4(x = 0.05, 0.1, 0.2, 0.3, 0.4, 0.5) is stable at 25–1400 °C within air atmosphere, and their high-temperature TECs (6.4–8.9 × 10−6K−1, 1400 °C) are effectively regulated by introductions of different contents of Al, which enlarge their engineering applications for SiCf/SiC and Al2O3f/Al2O3CMCs. The evolutions of TECs are analyzed from structural characteristics and phase compositions, and the increased TECs make Yb1−xAlxTaO4potential EBCs for Al2O3matrixes. Due to the high bonding strength of Al–O bonds, hardness, as well as Young’s modulus, are enhanced with the increasing Al content, with Yb1−xAlxTaO4(x = 0.05, 0.1, 0.2, 0.3, 0.4, 0.5) having a nano-hardness of 3.7–12.8 GPa and a Young’s modulus of 100.9–236.6 GPa. The TECs of YbTaO4are successfully regulated to expand their applications, and they match those of Al2O3and SiC matrixes, as well as displaying improved mechanical properties. This work promotes applications of YbTaO4as potential EBCs and provides a new way to regulate the TECs of tantalates.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2020
·
IF 6.155
Lin Chen,Mingyu Hu,Jun Guo,Xiaoyu Chong,Jing Feng
As candidate thermal/environmental barrier coatings (T/EBCs), the structure characteristics and comprehensive properties of monoclinic-prime (m') RETaO 4 (RE = Yb, Lu, Sc) with excellent Al 2 O 3 /SiO 2 chemical compatibility are studied. Excellent thermal insulation protection will be provided by m'RETaO 4 due to their low thermal conductivity (∼1.6 W m −1 K −1 , 900 °C) and prominent thermal radiation resistance, which is much better than those of YSZ (∼2.5 W m −1 K −1 , 1000 °C) and La 2 Zr 2 O 7 (∼2.0 W m −1 K −1 , 900 °C). The thermal expansion coefficients (TECs) are 3.0–8.0 × 10 -6 K −1 (200−1200 °C), which is suitable for T/EBCs applications. Furthermore, absence of phase transition and extraordinary chemical compatibility with Al 2 O 3 /SiO 2 up to 1500 °C indicate the potential application prospect. The documented governing mechanisms of m'RETaO 4 properties will enable researchers to promote their application in the future investigation.
研究领域:
材料科学
·
工程热物理
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）