JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2019
·Vol. 103
·期 4
·2727-2740
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IF 3.094
Fushuo Wu,Peng Wu,Yunxuan Zhou,Xiaoyu Chong,Jing Feng
In this work, RENbO 4 (RE = Y, La, Nd, Sm, Gd, Dy, Yb) ceramics with low density, low Young's modulus, low thermal conductivity, and high thermal expansion have been systematically investigated, the excellent thermo-mechanical properties indicate that RENbO 4 ceramics possess the potential as the new generation of thermal barrier coatings (TBCs) materials. X-ray diffraction and Raman spectroscopy phase structure identification reveal that all dense bulk specimens obtained by high-temperature solid-state reaction belonged to the monoclinic (m) phase with C12/c1 space group. The ferroelastic domains are detected in the specimens, revealing the ferroelastic transformation between tetragonal (t) and monoclinic (m) phases of RENbO 4 ceramics. The Young's modulus and hardness of the RENbO 4 ceramics measured by the NanoBlitz 3D nanoindentation method are discussed in details, and the lower Young's modulus (60-170 GPa) and higher hardness (the maximum value reaches 11.48 GPa) indicating that higher resistance of RENbO 4 ceramics to failure and damage. Lower thermal conductivity (1.42-2.21 W [m k] −1 at 500°C-900°C) and lower density (5.330-7.400 g/cm 3 ) than other typical TBCs materials give RENbO 4 ceramics the unique advantage of being new TBCs materials. Meanwhile, the thermal expansion coefficients of RENbO 4 ceramics reach 9.8-11.6 × 10 −6 k −1 and are comparable or higher than other typical TBCs materials. According to the first-order derivative of the thermal expansion rate, the temperature of the ferroelastic transformation of RENbO 4 ceramics can be observed.
研究领域:
材料科学
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固体力学
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DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2017
·Vol. 101
·期 3
·1266-1278
·
IF 2.841
Lin Chen,YeHua Jiang,XiaoYu Chong,Jing Feng
Thermal barrier coatings (TBCs) are one of the most important materials in gas turbine to protect the high temperature components. RETa 3 O 9 compounds have a defect-perovskite structure, indicating that they have low thermal conductivity, which is the critical property of TBCs. Herein, dense RETa 3 O 9 bulk ceramics were fabricated via solid-state reaction. The crystal structure was characterized by X-ray diffraction (XRD) and Raman Spectroscope. Scanning electron microscope (SEM) was used to observe the microstructure. The thermophysical properties of RETa 3 O 9 were studied systematically, including specific heat, thermal diffusivity, thermal conductivity, thermal expansion coefficients, and high-temperature phase stability. The thermal conductivities of RETa 3 O 9 are very low (1.33-2.37 W/m·K, 373-1073 K), which are much lower than YSZ and La 2 Zr 2 O 7 ; and the thermal expansion coefficients range from 4.0 × 10 −6 K −1 to 10.2×10 −6 K −1 (1273 K), which is close to La 2 Zr 2 O 7 and YSZ. According to the differential scanning calorimetry (DSC) curve there is not phase transition at the test temperature. Due to the high melting point and excellent high-temperature phase stability with these oxides, RETa 3 O 9 ceramics were promising candidate materials for TBCs.
研究领域:
材料科学
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热物理
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DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2022
·
IF 6.371
Wei Liu,Wenyu Tan,Yang Yang,Hanwei He
Efficient, stable, and environmentally friendly electrocatalysts urgently need to be explored for hydrogen evolution reaction (HER). A novel and facile nickel–selenium–dysprosium (Ni–Se–Dy) electrocatalyst was synthesized on Ni foam via simple and feasible one–step galvanostatic electrodeposition . The prepared Ni–Se–Dy electrodes showed excellent HER activity in alkaline medium with low overpotential values of 72 and 173 mV to deliver the current density values of 10 and 50 mA·cm −2 . Tafel slope value (119.72 mV·dec −1 ) for Ni–Se–Dy electrode in 1.0 M KOH indicated that the Ni–Se–Dy catalyst followed a Volmer–Heyrovsky mechanism, and the rate–determining step of this reaction was a Volmer step. Electrochemical test and scanning electron microscopy results showed that the excellent HER performance of Ni–Se–Dy electrode can be attributed to surface morphology , better intrinsic activity, and high conductivity.
研究领域:
材料科学
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电化学
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催化
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可再生能源
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DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Hongfeng Chai,Ying Li,Yifan Luo,Marc Debliquy,Chao Zhang
The early detection of lung cancer by breath analysis has attracted more and more attention. In this work, high-performance LnFeO 3 (Ln = Nd, Dy, Er) based isopropanol sensors were synthesized by microwave-assisted hydrothermal method. X-ray diffraction, field-emission scanning electron microscope, transmission electron microscope, and UV–visible-near infrared absorption spectrometer were used to analyze the material phase composition, microstructure, and other physical properties. The sensing performance was tested by using a four-channel gas testing chamber. The sensors were tested with low concentrations of isopropanol at high humidity to simulate a real human exhaled breath environment. The low binding energy of the Ln-O bond makes it easy to have chemical reactions, which leads to excellent isopropanol sensing performance. Finally, the gas sensing mechanism of the LnFeO 3 sensor was discussed.
研究领域:
材料科学
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医学诊断
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传感器技术
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DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2023
·
IF 5.7
Peixiong Zhang,Enhui Wang,Chunyu Guo,Tao Yang,Xinmei Hou
High-entropy rare earth phosphates (HE REPO 4 , RE = Ho, Tm, Yb, Lu, Dy, Er and Y) with xenotime structure have been successfully synthesized and comprehensively characterized to evaluate their feasibility as thermal/environmental barrier coatings (T/EBCs) applied in SiC f /SiC ceramic matrix composites (SiC-CMCs). HE REPO 4 show good chemical compatibility with SiO 2 at 1400 °C and excellent high-temperature stability up to 1750 °C. The thermal expansion coefficient (TEC) of HE (6RE 1/6 )PO 4 is 5.9 × 10 −6 /°C ranging from room temperature to 900 °C, which is close to that of SiC-CMCs. Compared with single-component REPO 4 , the thermal conductivity of HE (6RE 1/6 )PO 4 (from 5.1 W·m −1 ·K −1 at 100 °C to 2.8 W·m −1 ·K −1 at 1300 °C) is significantly reduced benefiting from larger lattice distortion. These allow HE REPO 4 to be a potential candidate as T/EBCs applied in SiC-CMCs.
研究领域:
材料科学
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陶瓷
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涂层
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DOI
高影响因子
Journal of Materials Chemistry B
·
2013
·Vol. 1
·期 10
·1491-1500
·
IF 0
Zhi-Gang Wang,Gong Cheng,Yan-Lin Liu,Ji-Lin Zhang,De-Hui Sun,Jia-Zuan Ni
The multifunctional microspheres consisting of the magnetic γ-Fe2O3 core and the affinity REVO4 (RE = Sm, Dy, Ho) shell have been synthesized via the homogenous precipitation–calcination–ion exchange three-step synthetic route. Their morphologies, structures, surface properties, and magnetisms were characterized, respectively. SEM and TEM images indicate that they all have an average size of about 400 nm and very rough surfaces. The TEM images further reveal that the γ-Fe2O3@REVO4 microspheres are all core–shell structures and the REVO4 shells are about 55–60 nm in thickness. The XRD pattern analyses show that the magnetic γ-Fe2O3 cores belong to cubic structure and the REVO4 (RE = Sm, Dy, Ho) shells are composed of their corresponding tetragonal major phases. HRTEM images, FTIR spectra and EDS further demonstrate the formations of tetragonal REVO4 shells based on checkup of the corresponding lattice fringes, characteristic IR absorption peaks and element signals. Their potentials for selective capture, rapid separation, and convenient mass spectra (MS) labeling of the phosphopeptides from complex proteolytic digests are explored and evaluated for the first time. The experimental results show that the magnetic γ-Fe2O3@REVO4 core–shell structured microspheres have high selective affinity for the phosphopeptides. The trapped phosphopeptides can be rapidly isolated by an external magnetic field, and can be easily identified by characteristic MS signals from 80 Da mass losses in the mass spectra (MS). Additionally, the γ-Fe2O3@REVO4 affinity materials can be reused after recovery.
研究领域:
材料科学
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分析化学
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生物化学
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DOI
PubMed
OPTICAL MATERIALS
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2021
·
IF 3.08
Panpan Du,Qi Zhu,Xiaodong Li,Xudong Sun,Byung-Nam Kim,Ji-Guang Li
A series of garnet-type Li 6 CaLa 2(1- x ) Nb 2 O 12 : x RE phosphors (LCLN: x RE, RE = Pr, Sm, Tb and Dy) were prepared via sol-gel processing and subsequent calcination for the first time, with the course of phase evolution and the characteristics of the LCLN host and RE 3+ luminescence being investigated in detail. It was found that ∼900–1000 °C is a suitable temperature for precursor calcination to produce the garnet phase and LCLN has a relatively low phonon energy (∼725 cm −1 ) and a relatively wide bandgap (∼4.53 eV) for luminescence. The LCLN:0.012Pr, LCLN:0.04Sm, LCLN:0.06 Tb and LCLN:0.06Dy typical phosphors were analyzed to have dominant excitation/emission bands at ∼278/489, 265/614, 268/549 and 264/581 nm, emission colors of white, orange, green and yellowish white, and fluorescence lifetimes of ∼0.43, 0.74, 0.90 and 0.44 ms, respectively. Temperature-dependent photoluminescence found that the four phosphors maintained ∼28, 37, 45 and 56% of their room-temperature intensities at 423 K, with activation energies for thermal quenching of ∼0.37, 0.29, 0.34 and 0.25 eV, respectively. The results demonstrated that the Li-stuffed LCLN garnet could be a suitable host for UV excitable multicolor phosphors.
研究领域:
材料科学
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光学
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DOI
高影响因子
CRYSTAL GROWTH & DESIGN
·
2025
·
IF 3.4
Yun Lv,Yanhong Wang,Yaling Dou,Ang Li,Jinkui Tang,Olga S. Volkova,Alexander N. Vasiliev,Hongcheng Lu
We report the synthesis and magnetic properties of three rare-earth magnetic compounds RE2O2CN2 (RE = Nd, Dy, Gd) with a frustrated triangular spin–lattice, as well as their thermal stability and Fourier transform infrared (FTIR) spectroscopy. The magnetic susceptibility results show paramagnetic behavior with no long-range order (LRO) down to 2 K in Nd2O2CN2 and Dy2O2CN2 due to spin frustration, which are further confirmed by the specific heat measurements, despite the large Curie–Weiss temperature for strong intralayer interaction through the RE–O–RE pathway (RE = Nd, Dy). While Gd2O2CN2 with a large spin exhibits LRO at 2.7 K, which should be caused by the non-negligible interlayer interactions. The field-dependent magnetization curves show a linear increase up to 7 T for Nd2O2CN2 and Gd2O2CN2, which are far from their saturation. While the magnetization of Dy2O2CN2 increases linearly below 3 T, then slowly increases to saturation, and the magnetization value is 6.62 μB at 7 T. Our work provides promising magnetic triangular lattice systems to further investigate frustration and quantum magnetism in rare-earth magnetic systems.
研究领域:
凝聚态物理
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材料化学
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磁性与磁性材料
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量子材料
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2020
·
IF 6.155
Daquan Liu,Yanxia Wang,Xue Jiang,Huijun Kang,Xiong Yang,Xiaoying Zhang,Tongmin Wang
Microstructural modifications and appropriate element doping are necessary to simultaneously enhance the electrical conductivities and reduce the lattice thermal conductivities of thermoelectric materials . Herein, we propose a strategy of multielement doping combined with a burial sintering process to promote thermoelectric properties. Three-element doped Sr 0.9 La 0.05 Dy 0.05 Ti 1− x Nb x O 3 ( x = 0, 0.05, 0.10, 0.15, and 0.20) powders were synthesized by high-energy ball milling, and corresponding bulk samples were prepared by carbon burial sintering. In the bulk samples, we obtained the desired microstructures composed of shell-vesicular architectures with dense dislocations and second phase particles. These materials had ultrahigh electrical conductivities (∼5300 S cm −1 at 300 K), low lattice thermal conductivities (∼1.6 W m −1 K −1 from 700 to 1100 K when x = 0.2) and low total thermal conductivities (minimum value of 2.95 W m −1 K −1 when x = 0.05 at 1100 K). The maximum zT values were 0.28 when x = 0.05 and 0.27 when x = 0.2 at 1100 K. This strategy provides a possible direction for improving the thermoelectric properties of SrTiO 3 based materials.
研究领域:
材料科学
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热电材料
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陶瓷
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固体物理
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能源材料
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DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2024
·
IF 8.1
Zhongyan Luo,Jukka Kuva,Jan Luyten,Risto Koivula,Małgorzata Szlachta,Hongli Bao,Junhua Xu
The increasing demand for Co, Nd, and Dy, particularly in neodymium iron boron (NdFeB) magnets, has heightened concerns over their supply risks. Developing efficient, environmentally friendly methods to recover Co, Nd, and Dy from spent NdFeB magnets is therefore critical. This study presents the synthesis of two types of crystalline zirconium phosphate (ZrP) encapsulated in polyacrylonitrile (PAN) composite beads. The structure, morphology, and chemical properties were analyzed using X-ray diffraction (XRD), thermogravimetry (TG), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray computed tomography (XCT), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET), and 31 P nuclear magnetic resonance (NMR). The intercalation of dimethylformamide (DMF) enlarged the interlayer spacing of α-ZrP and γ-ZrP, thereby enhancing their ion exchange properties. Batch sorption experiments revealed that α-ZrP/PAN outperformed γ-ZrP/PAN in both sorption and separation efficiency. α-ZrP/PAN beads exhibited high selectivity for Nd 3 + and Dy 3 + , with minimal Co 2 + sorption (8.57 %). Stepwise elution studies on α-ZrP/PAN demonstrated the obtained metal purities to be ∼100 wt% for Co, 64.1 wt% for Nd, and 96.5 wt% for Dy. Sorbent regeneration was investigated over ten sorption–desorption cycles, which revealed that α-ZrP/PAN retained 72.72 % of its sorption capacity, demonstrating excellent reusability and stability, while γ-ZrP/PAN’s capacity declined to 68.95 % after five cycles. The ion-exchange reaction accompanied by shrinking of the interlayer space was illustrated by combining the batch sorption experiments, column operations, and analyses from XRD, FT-IR, and X-ray photoelectron spectroscopy (XPS). Overall, α-ZrP/PAN shows promise for Co, Nd, and Dy separation from NdFeB magnets, although further optimization of sorbents and elution agents is necessary.
研究领域:
材料科学
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环境工程
·
化学工程
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产品关联
DOI
高影响因子
Polymers
·
2023
·Vol. 15
·期 9
·2077
·
IF 5
Longfei Zhang,Ying Wang,Limin Peng,Zhilin Chen,Shaoyi Lyu,Siqun Wang
Long-term relief of indoor volatile pollution has become a competitive issue worldwide in both visible and dark environments. A novel self-luminous wood coating with carbon dots (CDs)/titanium dioxide (TiO2) nanomaterial coated SrAl2O4: Eu2+, Dy3+(CDs/TiO2@SAO) composite was prepared for the long-term degradation of formaldehyde through a simple sol-gel method. The microstructure, chemical composition, ultraviolet-visible (UV-vis) spectra, and long-lasting fluorescence of the CDs/TiO2@SAO photocatalyst were analyzed to illustrate the mechanism for degrading formaldehyde. The obtained CDs with a particle size of ~2–7 nm have a good graphite structure and presented good absorption in visible light. In addition, owing to the synergistic effect of the CDs/TiO2nanomaterial coating layer and the long-afterglow luminescence of the SAO phosphor, the CDs/TiO2@SAO composite can absorb a part of the visible light for photocatalytic degradation and store luminous energy efficiently at daytime so as to give out visible luminescence continuously for a few hours in the darkness. Furthermore, the functional wood coatings with CDs/TiO2@SAO composite presented continuous and efficient photocatalytic activity in the presence and absence of light exposure. The current research could provide a new strategy for designing an efficient photocatalyst for degrading formaldehyde pollution in the daytime with a visible light supply and in an indoor dark environment without an external light source.Keywords:carbon dots;core-shell microspheres;SrAl2O4: Eu2+, Dy3+phosphor;titanium dioxide;surface modification;photocatalytic degradation
研究领域:
材料科学
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环境科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
·
2026
·
IF 14.3
Binbin Ning,Junyao Wu,Sai Liu,Jinwei Guo,Xiaopeng Hu,Qing Liu,Wang Zhu
A series of five (5RE 0.2 )Ta 3 O 9 high-entropy ceramics (RE = La, Gd, Nd, Dy, Sm, Eu, Ce) is successfully synthesized via a solid-state method. Their temperature-dependent fracture toughness is systematically investigated across the 25–1200 °C range, using in situ three-point bending tests coupled with the digital image correlation method. The fracture toughness exhibits a non-monotonic variation: it peaks at 2.3 MPa m 1/2 at room temperature, then sharply declines to a minimum of 1.5 MPa m 1/2 at 400 °C. Subsequently, an anomalous rebound to approximately 2.1 MPa m 1/2 is observed at 800 °C, followed by a further decrease, stabilizing between 1.7 and 1.9 MPa m 1/2 at 1200 °C. High-temperature X-ray diffraction and high-resolution transmission electron microscope results confirm an irreversible orthorhombic-to-tetragonal phase transformation occurring between 600 and 800 °C. Aberration-corrected STEM provides direct atomic-scale evidence of a high-density dislocation network interacting with crack tips, revealing dislocation pinning, bridging, and crack deflection. The combined action of phase-transformation-induced lattice strain and dislocation-mediated toughening effectively suppresses linear crack advance and enhances energy dissipation, thereby accounting for the partial recovery of fracture toughness at 800 °C. These direct observations establish a distinctive synergistic toughening mechanism in high-entropy ceramics, in which irreversible phase transformation and thermally activated dislocation networks cooperate to improve high-temperature fracture resistance.
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高影响因子
危险品化学品经营许可证（带存储）