JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Bowen Chen,Chenxia Li,Degang Deng,Fengping Ruan,Ming Wu,Le Wang,Yanting Zhu,Shiqing Xu
In this study, Eu 2+ /Eu 3+ coexisting perovskite LaAlO 3 phosphors were synthesized by a traditional high-temperature solid-phase reaction method and investigated via X-ray diffraction data, X-ray photoelectron spectroscopy and temperature-dependent photoluminescence spectra. The Eu 2+ /Eu 3+ coexisting LaAlO 3 phosphors exhibit excellent optical temperature sensing characteristics and are potential inorganic materials for temperature detection. The measured maximal absolute temperature sensitivity reaches 0.014 K -1 , and the corresponding largest relative temperature sensitivity is 1.193% K −1 , which are superior to most of previous reports of that. Meanwhile, the monitored signal peaks are well separated, providing a good signal discriminability. The energy level crossover relaxation of Eu 2+ and Struck-Fonger crossover process involving O 2– -Eu 3+ charge transfer band were used to explain the different temperature-dependent responses of Eu 2+ and Eu 3+ . This work may give new ideas for the future research of optical thermometric materials with high sensitivity and high discriminability.
研究领域:
材料科学
·
无机化学
·
光学工程
·
传感器技术
·
固体物理
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2024
·
IF 5.8
Yao Wang,Jiabin Jiang,Zhenyu Wang,Haitao Wang,Zihao Chen,Xiaolu Liang,Zimeng Pan,Jiachen Wang,Jiankun Sun,Jun Ma,Xuexing Jiang,Xin Gu,Xiang Liu
Herein, the electrical transport properties of La 0.76 Ba 0.24 MnO 3 (LBMO) films were investigated by preparing LBMO films using the sol-gel method and varying the sintering temperature. The results show that the surface morphology of the films exhibits a homogeneous and compact microstructure, characterized by a three-dimensional island-like growth pattern, which remains consistent across various sintering temperatures. The LBMO film exhibits a crystal structure of R 3 ̅ c in the sintering temperature ( T s ) range of 1373–1448 K. With the increasing of T s , the full width at half maximum of the diffraction peaks {012}, {024} and {312} of the LBMO films gradually decreases, meaning the films crystallinity is significantly improved. At the same time, the internal strain of the LBMO films decreases, resulting in the change of the MnO 6 octahedron, and has an impact on the electronic transition and the electron-phonon coupling. The DE mechanism is increase and then decrease with increasing T s . With the increase of T s , the metallicity of the film samples decreases, and the insulating property increases, the overall change of the metal-insulator transition temperature ( T p ) of the film samples is not significant, the resistivity firstly decreases and then increases; T k slightly decreases, the peak TCR firstly increases and then decreases, and when T s = 1398 K, T k = 298.14 K, the TCR reaches the maximum value of 10.20 % K -1 . The results show that the change of the sintering temperature can obtain a high value of the room-temperature TCR .
研究领域:
材料科学
·
凝聚态物理
✓ 已验证
产品关联
DOI
高影响因子
Inorganic Chemistry Frontiers
·
2022
·Vol. 10
·期 2
·638-650
·
IF 7.779
Siyuan Li,Chenyu Zhang,Qi Zhu,Ji-Guang Li
Zero-phonon line (ZPL) emission of Mn4+, without the participation of phonons, is tightly related to the host crystal structure. However, the intensity of the intrinsic ZPL is much weaker than that of Stokes and anti-Stokes vibrational bands, and it always leads to a discontinuous emission peak. Regulating the ZPL of Mn4+ for a strong emission is very important but remains a challenge for perovskite-type oxides. Here, novel La1−xBaxAl1−xTixO3:0.001Mn4+ (LBAT:0.001Mn4+, x = 0–0.2) and La1−yYyAl1−yGayO3:0.001Mn4+ (LYAG:0.001Mn4+, y = 0–0.2) samples were successfully synthesized through a high-temperature solid-state reaction, and a tunable ZPL of Mn4+ was found by cationic pair substitution of Ba2+–Ti4+ and Y3+–Ga3+ for La3+–Al3+ in LaAlO3:Mn4+. The ZPL intensity is related to the local symmetry around Mn4+ and the ZPL energy corresponds to the Mn–O bond distance and the O–Mn–O bond distortion. Through co-doping Ba2+–Ti4+, the ZPL at 710 nm is enhanced and the intensity increases continuously with increasing the x value, due to the local symmetric degree of Mn4+ decreasing slowly. However, Y3+–Ga3+ co-doping induces a linear and quick increase in the intensity of ZPL at 704 nm with increasing y value, due to the local symmetric degree of Mn4+ decreasing quickly. The octahedral tilting distortion is very important for the local symmetry. Ba2+–Ti4+ co-doping reduces octahedral tilting distortion, but Y3+–Ga3+ co-doping induces a serious octahedral tilting distortion. Consequently, the ZPL emission exhibits an octahedral-tilting dependent behavior. Mainly due to the larger distortion of the O–Mn–O bond, the energy of ZPL for LYAG:0.001Mn4+ is higher than that for LBAT:0.001Mn4+. The outcomes of this work provide a promising way to regulate the ZPL intensity and energy by tuning the local structure around Mn4+, and may have wide implications for Mn4+-doped phosphors and solid-state lighting.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Research and Technology-JMR&T
·
2022
·
IF 6.267
Song-Tao Dong,Xin Ye,Zhuang Fu,Xiaoyun Jin,Junlin Wei,Lei Wang,Ya-Mei Zhang
In this study, a series of La 1−x Sr x AlO 3 (x = 0.0, 0.1, 0.15, and 0.2) nanotubes were prepared by electrospinning method, and their morphological and electrochemical properties were characterized. The results show that the La 1−x Sr x AlO 3 (x = 0.0, 0.1, 0.15, and 0.2) nanotubes exhibit a distinct hollow structure, the average diameters of the nanofibers are ∼75 nm, 70 nm, 95 nm, and 142 nm. The electrochemical results show that the La 1−x Sr x AlO 3 nanotubes have excellent electrochemical performance, and the maximum specific capacitance of 180 F/g for the La 0.9 Sr 0.1 AlO 3 . After 1500 charge–discharge cycles, the specific capacitance of the La 0.9 Sr 0.1 AlO 3 electrode retained ∼99%, indicating that it has good cycling stability and long service life. This provides a promising electrode material for supercapacitors.
研究领域:
材料科学
·
电化学
·
纳米材料
·
能源存储
·
功能陶瓷
·
电容器
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Shen Zhou,Zhoufu Wang,Zhenghuang Quan,Hao Liu,Yan Ma,Pingtao Fang,Chao Shu
Yttrium oxide materials exhibit excellent vacuum and high-temperature chemical stability as well as low wettability with alloys, making it ideal for superalloy smelting. However, its poor sinterability and low fracture toughness, which result in poor thermal shock resistance significantly limit its service life. This study focuses on yttrium oxide materials. By incorporating ferroelastic functional unit characteristics, a pre-synthesized LaAlO 3 phase with good intrinsic toughness was introduced into the Y 2 O 3 matrix. The effects of different LaAlO 3 contents on the phase composition, microstructure, mechanical properties, and thermal shock stability of the composite materials were systematically investigated. Results indicate that Y 2 O 3 /LaAlO 3 composite materials can be prepared successfully by regulating the La 3+ segregation behavior to form a transition layer at the phase boundary. This method can significantly enhance both the strength and toughness of materials through the ferroelastic domain switching effect and the solid solution effect. These mechanisms are capable of effectively improving the material's resistance to crack propagation and thermal stress relaxation, thereby improving the thermal shock resistance of the composites under thermal shock conditions. When 15 mol% LaAlO 3 was added to Y 2 O 3 , the fracture toughness of the composite material increased to 4.65 ± 0.14 MPa m 1/2 . The residual strength retention of the composite material increased from 36.50 % to 43.38 % after thermal shock. Therefore, by constructing a phase boundary transition layer through La 3+ ion solid-solution, Y 2 O 3 /LaAlO 3 composite materials can be prepared, effectively enhancing both the mechanical properties and thermal shock resistance of Y 2 O 3 matrix ceramics, offering a viable strategy for designing high-performance oxide ceramics.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED ELECTROCHEMISTRY
·
2026
·Vol. 56
·期 10
·215
·
IF 3.7
Huang Haoyu,Guan Siqi,Zhang Bo,Huang Xiaotong,Zhang Baoshan,Li Lixiang,Zhang Han,An Baigang,Yang Haiming,Sun Chengguo,Geng Xin
Thermodynamic and electrochemical chemical kinetics instability between the electrode/electrolyte interface, resulting from bulk structural instability and Li + diffusion kinetics, were the key restraining factors for improving the energy and power density of Ni-rich layered oxide cathodes. These issues had become barriers to enhancing the high temperatures and high rates performance. Herein, a perovskite-phase LaAlO 3 coating was introduced on the pristine NCM811 surface to form a protective layer by a wet chemical method and high temperature solid-state reaction. The robust LaAlO 3 and derived Li 0.5 La 2 Al 0.5 O 4 layer clearly alleviated the residual lithium compounds, side reactions and phase transitions. Compared to the pristine NCM811, The pristine NCM811 coated with 2 wt% LAO 3 displayed the discharge capacities of 200 mAh g − 1 at 0.1 C, the capacity retention of 93.7%, 89.9% and 78.67% at 2.8–4.3 V, 200 cycles, 1 C (25℃), 1 C (50℃) and 10 C (25℃), demonstrating expectative stability and high-rate performance. Particularly, despite NCM811-LAO2 raw material was exposed in the atmosphere for 60 days, the initial capacities less than 5.0% was lost, exhibiting superior shelf performance. These findings underscored the potential of perovskite-phase coating as an effective and scalable surface modification strategy for enhancing the durability and rate capability of Ni-rich layered cathodes. Graphical
✓ 已验证
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2023
·
IF 5.7
Xinglai Yuan,Qinghu Wang,Wei Luo,Cuijiao Ding,Liang Huang,Yibiao Xu,Xiong Liang,Liping Pan,Shaobai Sang,Yawei Li,Haijun zhang,Jiangtao Li
Ca 2+ /Cr 3+ co-doped LaAlO 3 has been considered as important ceramic to achieve energy-savings in thermal equipment due to excellent infrared radiation (IR) performance. However, following problems restricted its industrial applications: one is the correlation between emissivity and the valence state of Cr which is not clear, then there is no quantitative evaluation of Cr 6+ content in ceramics. In this work, Ca 2+ /Cr 3+ co-doping LaAlO 3 ceramics have been fabricated. By adjusting Ca 2+ /Cr 3+ doped ratio (0 ≤ n (Ca 2+ )/ n (Cr 3+ ) ≤ 0.75), the “Cr 3+ →(Cr 4+ /Cr 6+ )” transformation ratio has been controlled. The results show that a higher concentration of Cr 4+ in the material can significantly enhance the emissivity, while Cr 6+ has no such effect. In addition, the Cr 6+ content was measured by leaching method and high-temperature volatilization methods, respectively. This work can be used to guide the fabrication of environment-friendly Ca 2+ /Cr 3+ co-doped LaAlO 3 -based ceramics with high emissivity in the field of energy-saving for thermal equipment.
✓ 已验证
产品关联
DOI
高影响因子
Advanced Electronic Materials
·
2022
·Vol. 8
·期 9
·2101414
·
IF 7.633
Chao Du,Di Zhou,Rui-Tao Li,He-Tuo Chen,Guo-Hong Zhou,Bin Tang,Moustafa Adel Darwish,Song Xia,Zhuo Xu
In this paper, the medium dielectric constant 0.65CaTiO 3 -0.35LaAlO 3 (CTLA) composite microwave ceramic is employed to introduce in dielectric patch antennas (DPA). Typical, high-performance microwave dielectric properties of ε r ≈ 44.8, Q × f ≈ 43 950 GHz@3.67 GHz and TCF ≈ 0 ppm °C –1 can be obtained by solid-state reaction method in CTLA composite microwave ceramics sintered at 1450 °C for 2 h. Then, the CTLA composite ceramic patch fired with silver coating is mounted on the Rogers RO4003C substrate operating as a magnetic wall boundary. A simplified cavity-like theoretical model is used to analyze the proposed DPA structure and the accuracy of this antenna model is evaluated by the theoretical results from a commercial CST Microwave Studio 2019. Based on this, the CTLA composite ceramic physical property is modified to enhance the radiation efficiency and reduce profile of the DPA. The higher-order TM 121 mode is brought close to the dominant TM 101 mode by taking advantage of the multimode characteristics of the dielectric patch resonator and introducing a sintered silver slot in the ceramic dielectric patch. For demonstration, the proposed DPA prototype operating in the multiprobe antenna near the field measurement system is implemented and measured.
研究领域:
电子工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2016
·Vol. 27
·期 6
·6382-6388
·
IF 1.798
Wang Yuxuan,Liang Weizheng,Huang Wen,Gao Min,Zhang Yin,Lin Yuan
Fe-doped BaTiO 3 thin films were grown on (001) oriented LaAlO 3 substrates using a polymer-assisted deposition technique. The microstructural and chemical state characters of the films with the Fe doping range from 1 to 10 at% were systematically investigated by X-ray diffraction and X-ray photoelectron spectroscopy. Evolution of the preferred orientation and strain status of BaTiO 3 films could be observed with increasing doping amount of Fe. Meanwhile, UV–Vis spectra of doped BaTiO 3 thin films showed that the band gap could be strongly affected by the doping amount of Fe with the smallest value at the Fe doping rate of 3 at%, which is proposed to be associated with the inevitable oxygen vacancies and the substitution of Ti ions by the Fe dopants.
研究领域:
材料科学
·
薄膜技术
·
凝聚态物理
·
光学材料
·
铁电材料
✓ 已验证
DOI
高影响因子
INORGANIC CHEMISTRY
·
2025
·
IF 4.7
Xiaomei Yu,Junwei Xu,Liang Guo,Jieqi Zhou,Rumeng Ouyang,Xiuzhong Fang,Jiating Shen,Xiang Wang
At present, there are still controversy viewpoints on the reactive oxygen sites in the OCM reaction on ABO3 perovskites. Some researchers believe that electron-deficient chemisorbed oxygen species (O2–, O22–, and O–) contribute to C2 product formation, and surface lattice oxygen (O2–) promotes the deep oxidation of methane, while others hold an opposite viewpoint. In addition, the influence of BOx polyhedra on the reactive sites and reaction performance has rarely been elucidated. Considering this, two types of LaAlO3 perovskites, comprising different contents of surface and bulk coordinatively unsaturated sites (AlO4 tetrahedra), were synthesized for the OCM reaction. Through a series of in situ and ex situ characterization techniques and combined with DFT calculations, a high oxygen vacancy concentration was revealed for the AlO4-rich LaAlO3 perovskite, leading to an abundance of reactive oxygen and promoting oxygen mobility. The study identified monatomic surface lattice oxygen O2– as the active sites for the deep oxidation of methane at low temperatures. The O22– species generated by oxygen vacancies promotes the formation of C2 products at high temperatures.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Chemistry C
·
2024
·
IF 5.7
Kai Ding,Wenye Deng,Jinyang Li,Ni Ai,Yan Xue,Xianghui Chen,Pengjun Zhao,Weiwei Meng,Aimin Chang,Yongxin Xie
This study synthesized La0.9X0.1AlO3 (X = Eu, Gd, Ho, Tm) and LaAlO3 ceramics by a solid-state method. The characterization of the ceramics revealed that the high degree of lattice distortion induced by variations in the size, mass, and electronegativity of rare-earth elements enhances high-temperature stability, leading to aging drift rates between 0.4% and 2.3% after 500 h at 1000 °C. Furthermore, the emergence of intrinsic defects and dislocations alters the charge conduction mode in LaAlO3, resulting in significant linearity at temperatures above 1000 K. This study further elucidates the transition in the charge conduction mechanism from thermally activated conduction to hopping conduction, which is driven primarily by oxygen vacancies and dislocations. DFT calculations support these findings, demonstrating a reduction in the band gap and increased carrier concentration. This work paves the way for the development of advanced NTC thermistors for reliable temperature monitoring in challenging environments.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2025
·
IF 9.5
shangmeng ning,jiahao Qi,Yuan Liu,Yongdan Li,Cuijuan Zhang
The perovskite-based materials are widely studied in heterogeneous catalysis; however, the low surface area seriously limits their practical application. Herein, this work proposes a strategy to prepare high surface area perovskite, by in-situ interfacial reaction between the loaded metal ions and the support. Specifically, lanthanum and nickel ions are sequentially loaded onto the commercial alumina support to prepare Al2O3 supported Ni-doped LaAlO3 for dry methane reforming as a case study. The properties of the resultant Ni-doped LaAlO3 strongly depend on the ratio of La to Al. Increasing La:Al from 0.1 to 1.0 leads to decrease in specific surface area, the sample with La:Al of 1.0 still delivers high surface area of 32 m2/g. Such high surface area renders the catalysts high robustness towards variation in space velocity and feed gas composition. The Ni nanoparticles exsoluted from the perovskite matrix are much smaller and higher dispersion compared with the La-free sample, which contribute to the high capability towards CH4 and CO2 activation. The higher content of medium and strong basic sites substantially promotes the stability over 200 h. The samples with La:Al of 0.1 and 0.5 show only ~1% decreases in activity compared with 3% for La-free sample. The sample with La:Al of 0.1 shows the highest activity and stability, CH4 and CO2 conversion and H2/CO of 92.3%, 88.1% and 0.91, respectively, at 120,000 mL/(h·gcat). The strategy proposed in this work is believed to spur the study on the perovskite-based catalysts and thus promote their practical application. Furthermore, the strategy can be extended to prepare other types of complex catalysts such as spinel and pyrochlore of high surface area.
✓ 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）