INORGANIC CHEMISTRY
·
2012
·
IF 4.601
Wenlong Yin,Wendong Wang,Lei Bai,Kai Feng,Youguo Shi,Wenyu Hao,Jiyong Yao,Yicheng Wu
The 12 new rare-earth tellurides Ba2MLnTe5 (M = Ga and Ln = Sm, Gd, Dy, Er, Y; M = In and Ln = Ce, Nd, Sm, Gd, Dy, Er, Y) have been synthesized by solid-state reactions. The two compounds Ba2GaLnTe5 (Ln = Sm, Gd) are isostructural and crystallize in the centrosymmetric space group P1̅, while the other 10 compounds belong to another structure type in the noncentrosymmetric space group Cmc21. In both structure types, there are one-dimensional anionic 1∞[MLnTe5]4– chains built from LnTe6 octahedra and MTe4 (M = Ga, In) tetrahedra, but the connectivity between the LnTe6 octahedra and MTe4 tetrahedra is different for the two structure types. On the basis of the diffuse-reflectance spectra, the band gaps are around 1.1–1.3 eV for these compounds. The Ba2MLnTe5 (M = Ga and Ln = Gd, Dy; M = In and Ln = Gd, Dy, Er) compounds are paramagnetic and obey the Curie–Weiss law, while the magnetic susceptibility of Ba2InSmTe5 deviates from the Curie–Weiss law. In addition, electronic structure calculation on Ba2MYTe5 (M = Ga, In) indicates that they are both direct-gap semiconductors with large nonlinear-optical coefficients.
研究领域:
材料科学
·
凝聚态物理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2013
·
IF 2.39
Zhongshan Ren,Xiaojun Hu,Xiangxin Xue,Kuochih Chou
The solid state reactions in Fe 3 O 4 –TiO 2 system has been studied by diffusion couple experiments at 1323–1473 K, in which the oxygen partial pressure was controlled by the CO–CO 2 gas mixture. The XRD analysis was used to confirm the phases of the inter-compound, and the concentration profiles were determined by electron probe microanalysis (EPMA). Based on the concentration profile of Ti, the inter-diffusion coefficients in Fe 3 O 4 phase, which were both temperature and concentration of Ti ions dependent, were calculated by the modified Boltzmann–Matano method. According to the relation between the thickness of diffusion layer and temperature, the diffusion coefficient of the Fe 3 O 4 –TiO 2 system was obtained. According to the Arrhenius equation, the estimated diffusion activation energy was about 282.1 ± 18.8 kJ mol −1 .
研究领域:
材料科学
·
物理化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2018
·Vol. 54
·期 5
·4115-4123
·
IF 2.993
Zhou Xiang,Zhu Ying,Ke Xiang,Zhang Kaili
In this study, we use simultaneous differential scanning calorimetry and thermogravimetric analysis to analyze the solid-state reaction characteristics of Al/Fe 2 O 3 nanothermites before n -Al melts. Different experimental setups for thermal analysis are compared, and the heat-release characteristics are studied on Al/Fe 2 O 3 nanothermites in the form of powder and pellet, respectively. It is found that protection provided by mere argon flow is far from enough for thermal analysis of Al/Fe 2 O 3 nanothermites. The experimental setup must be free of oxygen; otherwise, the determined exothermic peak is mostly the oxidation of n -Al by the residue oxygen molecules in the furnace body, due to the high reactivity and moderate accessibility of free oxygen molecules. Under proper experimental setup, it is found that besides the redox reaction between n -Al and n -Fe 2 O 3 , intermetallic reaction also occurs to form Fe 4 Al 13 . Moreover, the intermetallic reaction is more noticeable for nanothermite pellet than for nanothermite powder, and the eutectic reaction of Fe 4 Al 13 and n -Al leads to melting peaks below 655 °C. The results indicate that instrument configuration and sample status affect the testing results to a large extent, and one should be prudent to derive reaction characteristics of nanothermites.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2016
·
IF 2.758
W.Z. Sun,J.G. Cheng,Z.K. Huang,Y. Jiang,L.E. Wu,L.M. Liu
During investigation of the phase relations in the SiC–ZrO 2 –CaO ternary system, it was revealed that ZrO 2 reacted with SiC and CaO to form ZrC and calcium silicate via a series of solid-state reactions. Because these reactions may provide a new route to reaction-sintering of ZrC ceramics, ZrC/SiC and ZrC/salt composites, the formation process of the ZrC phase was analyzed. Subsolidus phase diagram of the related SiC–SiO 2 –ZrC–ZrO 2 –CaO (Si–Zr–Ca–O–C) quinary system at 1400 °C was presented.
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
Energy & Environmental Science
·
2024
·Vol. 17
·期 14
·5147-5161
·
IF 32.4
Qingfeng Fu,Wang Zhou,Peng Gao,Hongliang Dong,Shi Chen,Changling Fan,Jilei Liu
Fluorophosphate compounds are an important class of cathode materials; however, the one-step synthesis of phase-pure fluorophosphate compounds in a well-controlled manner remains challenging owing to the facile volatilization of fluorine during heat treatment. Herein, the rapid, facile, and scalable preparation of phase-pure fluorophosphates (e.g. KVPO4F) was successfully realized via a one-step solid-state reaction through the addition of PVDF, which served as an effective fluorine-compensating, vanadium-reducing, and in situ carbon-coating agent. In-depth mechanistic study showed that carbene (:CH2) generated upon PVDF decomposition could be easily recombined to form a ˙CH2(CH2)nCH2˙ alkyl biradical, and both were able to catalyze C–F bond breakage in fluorocarbon gases (C2F4) and therefore plays a pivotal role in promoting the formation of phase-pure fluorophosphate. The resultant cathode enabled a superior potassium-storage capability, including high specific capacity, excellent rate capability, and good cycling stability. The generality of the as-proposed synthetic strategy was also validated through the successful preparation of other fluorophosphate compounds.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
MATERIALS LETTERS
·
2023
·
IF 3
Xue Xing,Weiwei Cao,Zhaoxin Wu,Xiaohong Bai,Jiarui Gao,Xiaozhen Liang,Bo Wang,Chao Wang,Dalian Shi,Linwei Lv,Yonglin Bai
Fluorescence lifetime of phosphors is a critical index in the field of high energy physics and astrophysical detection. A series of ZnS x O 1- x :0.05Ce 3+ phosphors with tunable short fluorescence lifetime were prepared by performing high temperature solid state reaction method. The phosphors exhibited two mixed phases consisting of the hexagonal phase ZnO and the hexagonal phase ZnS. They are spherical and the average particle size is 2.24 μm. As the component content of the ZnS in ZnS x O 1- x :0.05Ce 3+ phosphors varies, the emission wavelength can be tuned from 448 nm to 495 nm, the short fluorescence lifetime can be tuned within the range of 6 μs–200 μs. By performing exponential fitting, we obtained the equation for the variation of fluorescence lifetime of ZnS x O 1- x :0.05Ce 3+ phosphors with ZnS fraction.
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 SOLID STATE CHEMISTRY
·
2020
·
IF 2.726
Xiaofen Wang,Jiang Ma,Xirui Lu,Zhiwei Fang,Lingshuang Li,Linyan Li,Yushan Yang
Hollandite ceramics are considered as a promising host matrix for cesium immobilization. In the paper, [Cs x Ba y ][Fe 3+ 2 y + x Ti 4+ 8-2 y - x ]O 16 (0.3 ≤ x , y ≤ 0.75) ceramics were synthesized by solid-state reaction method using 133 Cs and 133 Ba as the substitutes for radioactive Cs and its daughter product Ba. It was found that the as-prepared (Cs,Ba)-hollandite solid solution shows a tetragonal structure ( I 4/m) with >90% crystallinity and good Cs retention at 1250 °C. Moreover, the normalized release rates of Cs and Ba are in the order of 10 −3 g m −2 d −1 for 28 days, exhibiting excellent aqueous durability.
研究领域:
材料科学
·
核废物管理
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF RARE EARTHS
·
2018
·
IF 2.524
Weimin Li,Faqin Dong,Liang Bian,Hao Zou,Mianxin Song
In this study, Ce-doped zirconolite was synthesized through high-temperature solid-state reaction at 1250 °C in air for 96 h. The crystal phase, microstructure and valence transition were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). Phase relations of CaZr 1– x Ce x Ti 2 O 7 systems were determined by XRD analyses and Rietveld refinements . Four different phases are identified, namely zirconolite, perovskite , pyrochlore, and cerianite. The phase transformation (2M-zirconolite → 4M-zirconolite → Ce-pyrochlore) is caused by cations rearrangement as cerium content increases. The solubility limit of cerium ions in CaZr 1– x Ce x Ti 2 O 7 system is estimated to be approximately 0.80. Under sintering air atmosphere, partial reduction of Ce 4+ in Ce 3+ is detected in Ce 3d XPS spectra, and the ratio of Ce 3+ and Ce 4+ significantly decreases as cerium content increases.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2017
·
IF 3.454
Yi Ding,Hui Dan,Xirui Lu,Xiaoyan Shu,Zhihao Hong,Shuai Zhang
A series of Zr 1- x Nd x O 2- x /2 (0 ≤ x ≤ 1) ceramics was prepared by solid-state reaction method. The effects of Nd content on the phase evolution were investigated. The chemical durability of resulting waste forms was also examined. The results show that the ceramics with x < 0.1 show monoclinic and cubic zirconia phase, with 0.2 ≤ x < 0.4 exhibit a single cubic phase, with 0.4 ≤ x ≤ 0.6 exhibit a single pyrochlore phase, with 0.6 < x < 0.8 exhibit a single cubic phase and remain cubic phases and hexagonal Nd 2 O 3 when 0.8 ≤ x ≤ 1. The unit cell parameters of the Nd-doped zirconia samples increase as the Nd content increases. Moreover, the normalized element release rates of Nd element in Nd-doped zirconia ceramics firstly decrease with leaching time and almost no change after 21 days (∼0 −6 g m −2 d −1 ), demonstrating its good chemical durability.
研究领域:
材料科学
·
核废料管理
✓ 已验证
DOI
高影响因子
OPTICAL MATERIALS
·
2016
·
IF 2.183
Renping Cao,Zhihui Shi,Guanjun Quan,Zhiyang Luo,Pengjie Tang,Hui Ao,Xiaoguang Yu
Novel double perovskite Li 3 Mg 2 NbO 6 :Mn 4+ deep red-emitting phosphor is synthesized by solid-state reaction method in air. Emission band peaking at ∼670 nm with chromaticity coordinates (0.722, 0.278) is observed in the range of 600–780 nm due to 2 E → 4 A 2 transition of Mn 4+ ion. Excitation spectrum monitored at 670 nm contains three excitation bands peaking at ∼310, 395, and 470 nm within the range 220–600 nm, which indicate that Li 3 Mg 2 NbO 6 :Mn 4+ phosphor can be excited by ultraviolet, near ultraviolet, and blue light-emitting diode chips. The optimal Mn 4+ doping concentration is about 0.4 mol%. Fluorescence lifetime decreases from 0.485 to 0.32 ms with increasing Mn 4+ ion concentration from 0.2 to 1.2 mol%. Time resolved emission spectra and lifetime data confirm that there is only a single type of Mn 4+ ion luminescent center in Li 3 Mg 2 NbO 6 :Mn 4+ phosphor. The possible luminous mechanism of Mn 4+ ion is analyzed by Tanabe–Sugano energy diagram.
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 THE AMERICAN CERAMIC SOCIETY
·
2022
·Vol. 106
·期 1
·274-284
·
IF 4.186
Hongpeng Zheng,Guoyao Li,Hezhou Liu,Yongmin Wu,Huanan Duan
A Ta-doped Li 7 La 3 Zr 2 O 12 (LLZTO) solid electrolyte is a promising candidate for all-solid-state lithium battery due to its high ionic conductivity and stability against lithium metal. In this work, physicochemical properties of both dry- and wet-milled LLZTO particles were investigated. Based on X-ray diffraction, Fourier transform–infrared, thermogravimetric analysis, and scanning electron microscopy results, it was confirmed that highly reactive LLZTO powder prepared in dry milling conditions exhibited faster size reduction, rougher surface morphology, fewer surface impurities, and less agglomerated particles, in contrast to those in wet milling conditions. Sintering these dry-milled powders at 1320°C for 10 min in the air via solid-state reaction produced dense ceramic pellets with a relative density of 97.4%. The room-temperature ionic conductivity for LLZTO pellet via the dry milling was determined to be 6.94 × 10 −4 S cm −1 . Li–sulfur batteries based on the pellets showed an initial discharge capacity of 1301 mA h g −1 and a coulombic efficiency of 99.82% when cycled at room temperature. The effect of the milled powder on the sintered pellets was discussed in terms of boundary mobility, pore mobility, and morphology.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2023
·Vol. 52
·期 42
·15484-15488
·
IF 4
Xiangyu Zhang,Yunlei Chen,Yongfang Sun,Fei Wang,Xiao-Dong Wen,Tian-Nan Ye
Wide application of novel materials often requires low-cost preparation methods. In this study, we present a simplified and facile preparation method for the [Ca24Al28O64]4+(e−)4 electride material (C12A7:e−). Successful preparation of the C12A7:e− electride was confirmed by XRD patterns and magnetic behavior analysis. The concentration of electrons in the prepared C12A7:e− powder was calculated to be approximately 2.23 × 1021 cm−3, as evaluated by iodometry and TPD. DFT calculations provided insight into the unique electronic structure of C12A7:e−. Additionally, the substitution of the Ca reductant with CaH2 led to a reduction in the solid-state reaction temperature from 1100 to 950 °C, which can be attributed to thermodynamic effects such as a reduction in ΔG°.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）