JOURNAL OF ALLOYS AND COMPOUNDS
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2025
·
IF 6.3
Shen Zhou,Zhoufu Wang,Zhenghuang Quan,Hao Liu,Yan Ma,Pingtao Fang,Chao Shu
Yttrium oxide is extensively utilized in high-temperature industries due to its excellent vacuum and high-temperature chemical stability. However, its applications are limited by poor thermal shock resistance, which arises from its intrinsic brittleness. The ferroelastic toughening phase LaAlO 3 offers significant fracture toughness, which is attributed to the ferroelastic domain-switching toughening effect. This study focuses on enhancing the properties of yttrium oxide using Y 2 O 3 , La 2 O 3 , and Al 2 O 3 fine powders as primary raw materials. Y 2 O 3 /LaAlO 3 composite materials are developed, and the LaAlO 3 phase is formed in situ within the Y 2 O 3 matrix. The effects of varying in situ-synthesized LaAlO 3 content on the phase composition, microstructure, mechanical properties, and thermal shock resistance of Y 2 O 3 /LaAlO 3 composite materials are investigated. The key findings are as follows: 1) The use of a Y 2-x La x O 3 solid solution, instead of pure yttrium oxide, as the matrix allows for the synthesis of the LaAlO 3 phase in situ within the matrix. This approach enables the coexistence of LaAlO 3 and yttrium oxide, resolving the issue of chemical compatibility between Y 2 O 3 and LaAlO 3 . 2) The solid solution effect of the Y 2-x La x O 3 matrix and the ferroelastic toughening effect of the LaAlO 3 phase collectively enhance the material performance. The addition of an appropriate amount of LaAlO 3 improves the sintering performance, strength, hardness, and toughness of yttrium oxide. These enhancements significantly improve the thermal shock stability of yttrium oxide materials. 3) The excessive formation of the in situ LaAlO 3 phase, driven by the LaAlO 3 reaction expansion effect, negatively impacts the sintering performance and toughness of yttrium oxide materials, thereby compromising their thermal shock stability. To address this issue, an optimal amount of in situ LaAlO 3 phase should be incorporated to achieve a balance between toughness and thermal shock stability in Y 2 O 3 /LaAlO 3 composite materials while preserving their hardness and strength.
研究领域:
材料科学
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陶瓷工程
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DOI
高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2016
·Vol. 122
·期 4
·1-6
·
IF 1.444
Cao Renping,Ceng Dong,Liu Pan,Yu Xiaoguang,Guo Siling,Zheng Guotai
LaAlO 3 :Mn 4+ and LaAlO 3 :Mn 4+ , Na + deep red-emitting phosphors are synthesized by a solid-state reaction method in air. Their crystal structures, lifetimes, and luminescence properties are investigated, respectively. PLE spectrum monitored at 730 nm contains three PLE bands peaking at ~276, 325, and 500 nm within the range 200–550 nm, and PL spectrum with excitation 325 nm exhibits two PL band peaks located at ~703 and 730 nm owing to anti-stokes vibronic sidebands associated with the excited state 2 E of Mn 4+ ion and the 2 E → 4 A 2 transition of Mn 4+ ion, respectively. The optimal Mn 4+ doping concentration is ~0.8 mol%. Lifetime of LaAl 0.992 O 3 :0.8 %Mn 4+ phosphor is ~0.92 ms. Na + ion as charge compensator can improve obviously the luminescence properties of LaAlO 3 :Mn 4+ phosphor due to the charge compensation. The luminous mechanism of Mn 4+ ion is explained by using Tanabe–Sugano diagram of Mn 4+ ion in octahedral crystal field. The contents of this paper will be helpful to develop novel Mn 4+ -doped materials and improve their luminescence properties.
研究领域:
材料科学
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光学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Yan Xue,Wenye Deng,Yuyu Liu,Xuelian Bai,Xianghui Chen,Pengjun Zhao,Ye Pan,Huimin Zhang,Aimin Chang,Yongxin Xie
A series of novel negative temperature coefficient (NTC) thermistor materials based on La 1- x Ce x AlO 3 (0 ≤ x ≤ 0.2) ceramics were synthesized via the solid-state route. X-ray diffraction results confirmed the successful doping of Ce in the La 1- x Ce x AlO 3 crystal and the formation of a good solid solution. Scanning electron microscopy results indicated that Ce doping is beneficial for grain growth and reduces the porosity of the samples. With the increase in the Ce doping amount, the average grain size increased from 2.1793 to 10.7344 μm, and densities of the ceramics increased from 93.15% to 99.26%. The temperature vs resistance curve indicated that Ce doping reduces the resistivity of LaAlO 3 materials, while reducing the B 200/1400 value of the LaAlO 3 ceramic. For a doping amount of 0.2, the B 200/1400 value of the LaAlO 3 ceramic decreased from 18175.1 to 4897.7K, and the resistivity at 1000 °C decreased from 68971.87 to 1105.15 Ω cm. In addition, the La 1- x Ce x AlO 3 (0 ≤ x ≤ 0.2) series materials exhibited good linear NTC characteristics. X-ray photoelectron spectroscopy results revealed that the resistivity of the LaAlO 3 materials decreased after Ce doping owing to the transformation between the Ce 4+ and Ce 3+ valence states，and the concentration of Ce 3+ increased with the increase in the Ce doping amount. Ce 3+ increases the concentration of oxygen vacancies , decreasing the resistance. Impedance analysis findings suggested that the resistance of the La 1- x Ce x AlO 3 (0 ＜ x ≤ 0.2) material mainly originates from the grain. These results indicate that Ce doping is an effective method to reduce the resistivity of LaAlO 3 . Consequently, La 1- x Ce x AlO 3 (0 ≤ x ≤ 0.2) is a promising material for NTC applications.
研究领域:
材料科学
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电子工程
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DOI
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2021
·Vol. 100
·期 3
·414-422
·
IF 2.326
Li Limin,Zhao Gaoyang,Lei Li,Li Chengshan
Herein, the chelated precursor solution (Mg/BzAc) was synthesized using magnesium acetate as raw material and benzoylacetone as chemical modifier. The prepared solution was coated on (00 l )-oriented LaAlO 3 (LAO) single crystal substrate to fabricate the MgO/BzAc gel films. First, ultraviolet absorption spectroscopy was employed to analyze the ultraviolet photosensitivity of the MgO/BzAc gel films and the characteristic absorption peak corresponding to π-π* transition in Mg/BzAc chelate rings was detected at the wavelength of 329 nm. It is found that the intensity of this peak decreased gradually with increase in UV irradiation time, which indicates that the MgO/BzAc gel films exhibit good ultraviolet photosensitive properties. Then, MgO crystalline films with biaxial texture were prepared by heat-treating MgO/BzAc gel films at 850 °C in air for 60 min. Finally, micro-patterned MgO films with biaxial textures were prepared on the LAO substrate using photosensitive sol-gel lithography in combination with the above heat-treatment process.
研究领域:
材料科学
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物理学
✓ 已验证
DOI
高影响因子
Journal of Cleaner Production
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2025
·
IF 10
Jian Gao,Yu Zhou,Bingran Wang,Wenxuan Luo,Peng Wu,Kai Shen,Yaping Zhang
Catalytic hydrolysis technology is a promising solution for carbonyl sulfide (COS) treatment, but it is still difficult to scale up due to the poor selectivity of H 2 S and low stability of the catalyst. Developing an efficient catalyst, therefore, remains a significant challenge. Although perovskite-based catalysts are widely utilized in various applications, they are less commonly applied to carbonyl sulfide hydrolysis. Moreover, the effects of doping modification and the hydrolysis reaction mechanism remain to be fully elucidated. Through extensive testing and evaluation of various lanthanide perovskite materials, LaAlO 3 has demonstrated excellent catalytic hydrolysis performance. At 100 °C, LaAlO 3 exhibits a COS removal efficiency of 37 % and an H 2 S selectivity of 52 %. After modification via potassium doping at the A-site, the catalyst achieves near-complete conversion of COS to H 2 S and maintains stable operation for extended periods under high space velocity. The adsorption energies of various adsorption sites were calculated using DFT, confirming the optimal adsorption sites for reactants COS and H 2 O. Water undergoes dissociative adsorption on the catalyst to form -OH groups, which then adsorb COS through the Eley-Rideal (E-R) mechanism, leading to the formation of the hydrolysis intermediate HSCO 2 − . Reactive oxygen species, on the other hand, facilitate the dissociative adsorption of H 2 O, leading to the formation of more surface hydroxyl groups. Meanwhile, calculations indicate that K doping significantly enhances the adsorption energy of the reactants. The structure and properties of the catalysts have been characterized using a variety of techniques. The results have shown that K doping increases the content of weak basic sites and O 2 − in LaAlO 3 . Consequently, the catalytic activity of La 0.8 K 0.2 AlO 3 prepared by the sol-gel method is enhanced, showing higher selectivity and stability. This work provides new solutions and insights for the application of perovskites in the field of environmental catalysis. Owing to its simple preparation method, low cost, and high efficiency, the modified LaAlO 3 catalyst exhibits excellent environmental and economic benefits.
研究领域:
环境催化
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材料科学
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化学工程
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产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2018
·
IF 3.057
Yayu Su,Xiaolei Li,Huiming Ji,Zhihao Zhao,Peng Zhang
The Ca 2+ -Mn 2+ doped LaAlO 3 was prepared by solid state reaction method, and the effects of different doping content of Ca 2+ and Mn 2+ ions on the infrared radiation properties of LaAlO 3 were investigated. The result showed that after doping Ca 2+ and Mn 2+ ions, the infrared radiation properties of LaAlO 3 significantly increased. When 40 mol% Ca 2+ and 50 mol% Mn 2+ ions were doped into LaAlO 3 , the average emissivity in the wavelength range of 1–22 µm was up to 0.90, which was higher than pure LaAlO 3 (0.71). The enhancement of infrared radiation properties of LaAlO 3 was mainly due to the decrease of band gap of LaAlO 3 , the increase of hole carriers absorption of energy, and the increase of lattice vibration absorption after doping Ca 2+ and Mn 2+ ions. Ca 2+ -Mn 2+ doped LaAlO 3 with high infrared radiation properties shows application prospect in the high temperature oxidation environment.
研究领域:
材料科学
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物理化学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Qing Wang,Ziyang Ruan,Jianyu Li,Zifan Zhao
Yttrium aluminum garnet (Y 3 Al 5 O 12 , YAG) is regarded as a candidate of thermal barrier coating material for its excellent thermal stability and corrosion resistance, yet the poor fracture toughness and the low thermal expansion coefficient are the roadblock that limits its application. In order to improve the fracture toughness and the thermal expansion coefficients, a series of Y 3 Al 5 O 12 composite ceramics toughened by ferroelastic LaAlO 3 second phase were prepared by in-situ synthesis method in this work. The prepared x LaAlO 3 /(1- x )Y 3 Al 5 O 12 composite ceramics ( x =10∼50%) exhibit superior fracture toughness (2.16 MPa·m 0.5 ∼2.63 MPa·m 0.5 ) with respect to single-phase Y 3 Al 5 O 12 (1.94 MPa·m 0.5 ), which is mainly attributed to the synergistic effects of ferroelastic toughening of second phase, residual stress toughening, and fine-grain strengthening. On the account of the synergistic effects of three toughening mechanisms, 0.2LaAlO 3 /0.8Y 3 Al 5 O 12 composite ceramic manifest the strongest fracture toughness (2.63 MPa·m 0.5 ), which is 36% improved compared with single-phase Y 3 Al 5 O 12 . In addition, the thermal expansion coefficients of x LaAlO 3 /(1- x )Y 3 Al 5 O 12 specimens (9.54∼9.97 × 10 -6 K -1 at 1200 °C) are larger than that of Y 3 Al 5 O 12 (9.25 × 10 -6 K -1 at 1200 °C). Especially, 0.5LaAlO 3 /0.5Y 3 Al 5 O 12 specimen exhibits the highest thermal expansion coefficient (9.97×10 -6 K -1 at 1200 °C), which improve by 7.78% compared to single-phase Y 3 Al 5 O 12 . The improved fracture toughness and the capable thermal expansion coefficients of LaAlO 3 /Y 3 Al 5 O 12 composite ceramics renders their promising aspect for thermal barrier coating application.
研究领域:
材料科学
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陶瓷工程
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产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2019
·Vol. 48
·期 20
·6738-6745
·
IF 4.052
Yibo Chen,Conghua Yang,Meiping Deng,Jin He,Yiqin Xu,Zhao-Qing Liu
As a potential far-red-emitting candidate for plant growth LEDs, Mn4+ activated oxide phosphors have brand-new application prospects. However, it remains a significant challenge to develop highly efficient far-red-emitting phosphors due to their intrinsic energy loss in a large Stokes shift. Herein, we present a rational charge compensation strategy with a fusible charge compensator MgF2 at the molecular level to synthesize a LaAlO3:Mn4+,Mg2+ far-red-emitting phosphor. Notably, MgF2 can play an essential role in the incorporation of Mn4+ into the crystal matrix during the high-temperature solid-state reaction process, and thus induce a highly luminescent phosphor with a quantum yield of 78.6% and appropriate thermal stability. The fabrication of a high-performance far-red-emitting phosphor-converted LED further identifies the application potential of the modified Mn4+ activated LaAlO3 phosphor. This finding sheds light on the further exploration of high-grade far-red phosphors.
研究领域:
材料科学
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光学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Physical Chemistry C
·
2025
·
IF 3.2
Jiangyu Yu,Yingbo Zhang,Decai Zhu,Wenliang Fan,Nan Wang,Yaohui Niu,Jiali Zhou,Chengjun Zhu
A major challenge for semiconductor ion fuel cells (SIFCs) is to design an electrolyte with proton transport properties so that it can maintain high ionic conductivity within relatively low temperatures. Herein, we develop a Sr and Mg codoped LaAlO3 electrolyte that facilitates efficient conduction of protons and oxygen ions by enriching oxygen vacancies and reducing the activation energy of ion conduction. The optimized electrolyte shows a low activation energy of 0.31 eV and demonstrates remarkably elevated ionic conductivity at low temperatures, e.g., 0.1994 S cm–1 at 550 °C. This is attributed to the significant increase in oxygen vacancies, which has been verified by XPS technology. Meanwhile, the Sr and Mg codoped LaAlO3 electrolyte exhibits remarkable proton transport properties, confirmed by proton filtration experiments, which provide further evidence for the improvement of the electrolyte ionic conductivity. As a result, the fuel cell with an optimized LaAlO3 electrolyte delivers an impressive peak power density of 977 mW·cm–2 with an open circuit voltage (OCV) of 1.126 V at 550 °C. Particularly, compared with the fuel cell with a pure LaAlO3 electrolyte, the peak power density is increased by 38.4%. The dual-ion doping strategy provides crucial insight into the further development of high ionic conductivity electrolytes for SIFCs.
研究领域:
材料科学
·
能源技术
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Ting Chen,Zhiliang Zhu,Zeyu Wang,Hua Zhang,Yanling Qiu,Daqiang Yin,Guohua Zhao
To develop an efficient catalyst with novel structure and limited metal release for enhanced PMS activation, a 3D hollow sphere like Cu-incorporated LaAlO 3 perovskite was synthesized based on soft chemical process with template-free. It was evaluated as the heterogeneous catalyst firstly to activate peroxymonosulfate (PMS) for the oxidative degradation of several typical pharmaceuticals in water. The mechanism study indicated a coaction of electron transfer and oxygen defects in this system. The obtained catalyst can promote electron transfer efficiency of Cu + /Cu 2+ cycle and provide abundant oxygen defects for catalytic oxidation, which is responsible for the generation of OH, SO 4 − and 1 O 2 . These active species played crucial roles in efficient degradation of thiamphenicol (TAP), diclofenac sodium (DCF), ibuprofen (IBF) and paracetamol (PR), achieving more than 95% removal within 30 min. The catalyst kept high removal efficiency over pH range from 5.0 to 9.1 and suppressed copper leaching in reaction process. Besides, the catalyst exhibited good performance for TAP degradation and mineralization in raw water matrixes from Taihu Lake Basin, which showed a possible practical application to the remediation of water pollution.
研究领域:
环境科学
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材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2026
·Vol. 109
·期 8
·e71138
·
IF 4.2
Yilin Jia,Zhoufu Wang,Hao Liu,Yan Ma,Yunjie Dong,Haokai Song,Huimin Yu,Siyuan Wu
In aerospace, metallurgy, and related fields, Y 2 O 3 ceramics have broad application prospects owing to their excellent high-temperature chemical stability; however, their widespread application is limited by poor thermal shock resistance. In this study, LaAlO 3 , a toughening phase with good chemical compatibility and excellent mechanical and thermal properties, was introduced into Y 2 O 3 ceramics via an in-situ reaction method to improve their thermal shock resistance. The property and structural evolution of Y 2 O 3 /LaAlO 3 multiphase ceramics under cyclic thermal shock and different thermal shock temperature differences were systematically investigated. The results show that the residual strength of the ceramics exhibited an exponential decreasing trend. After nine thermal shock cycles, the elastic modulus and fracture toughness of the Y 2 O 3 /LaAlO 3 multiphase ceramics were 144.6% and 121.5% of those of the Y 2 O 3 ceramics, respectively. LaAlO 3 hindered crack propagation through a pinning effect, while its ferroelastic domain-switching mechanism effectively dissipated stress at the crack tip. The crack-particle interaction model indicated that thermal shock cracking in the multiphase ceramics had a saturation limit. After nine cycles, the crack damage area per interaction reached approximately 90% of the damage tolerance, and the crack propagation rate continued to decrease. With increasing thermal shock temperature difference, the residual strength of the composite ceramics exhibited a nonmonotonic trend, with a residual strength retention of 73.1% after three thermal shock cycles from 800°C to room temperature. This can be attributed to the dissipation of strain energy by ferroelastic domain rearrangement and domain-wall motion during the LaAlO 3 phase transformation. In addition, the elastic softening associated with the phase transformation improved the strain compliance of LaAlO 3 , reduced local thermal stress, and mitigated damage in the ceramics.
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2020
·Vol. 31
·期 17
·14879-14885
·
IF 2.22
Niu Shuting,Jiang Juan,Wang Jinzhao,Gan Lin,Zhang Tianjin
0.67CaTiO 3 –0.33LaAlO 3 (CTLA) microwave dielectric ceramic materials with the additives of H 3 BO 3 , Li 2 CO 3 or H 3 BO 3 –Li 2 CO 3 were prepared by a conventional solid-state reaction method. The effects of the sintering additives on the densification behavior, phase compositions, microstructures, and microwave dielectric properties of the CTLA ceramic samples were investigated. It was found that the binary additive of H 3 BO 3 –Li 2 CO 3 effectively promoted the densification and lowered the sintering temperature of the CTLA ceramic samples without a significant decrease in their Q × f values. For example, with an addition of 0.2 wt% H 3 BO 3 –0.1 wt% Li 2 CO 3 , the optimal microwave dielectric properties of ε r = 45.5, Q × f = 31,771 GHz and a near-zero τ f of 2.43 ppm/℃ were obtained in the CTLA ceramic sample sintered at only 1175 ℃, which is significantly lower (~ 225 ℃) compared to the sintering temperatures of conventionally sintered CTLA ceramics.
研究领域:
材料科学
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电子材料
✓ 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）