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1.
Three-dimensional Zn3V2O7(OH)2·2H2O microspheres have been successfully synthesized by a simple and facile liquid phase precipitation method without using any surfactants or additives. The as-prepared microspheres were constructed by two-dimensional nanosheets, which interconnected with each other through self-assembly. The influences of the aging time, reaction temperature, and pH value on the morphologies of the products were systematically investigated. Moreover, three-dimensional Zn3(VO4)2 microspheres could be formed through calcination of the Zn3V2O7(OH)2·2H2O precursor. The obtained Zn3V2O7(OH)2·2H2O and Zn3(VO4)2 microspheres were further investigated as the anode materials of lithium-ion batteries. Electrochemical measurements showed that the Zn3V2O7(OH)2·2H2O and Zn3(VO4)2 microspheres exhibited high discharge capacity and good cycle stability, indicating potential anode candidates in advanced rechargeable lithium-ion batteries. It should be noted that this is the first report on the Zn3V2O7(OH)2·2H2O and Zn3(VO4)2 three-dimensional microspheres as anode materials in lithium-ion batteries. The present work will greatly expand the range of anode choices and could assist long-term endeavors in developing high capacity anode materials for lithium-ion batteries. 相似文献
2.
Xu Wang Yuanxun Li Jie Li Guoliang Yu Lin Zuo Huaiwu Zhang 《Journal of Materials Science: Materials in Electronics》2014,25(11):4720-4724
(1 ? x) Ca(Zn1/3Nb2/3) O3 ? xBa(Zn1/3Nb2/3)O3 (short for CZN/BZN, x = 0–1.0) ceramics were prepared and investigated through the “one-step synthesis method” method. The structure of the system was analyzed using X-ray diffraction. The microstructure of the sintered pellet was analyzed using scanning electron microscopy. Dielectric constant (εr), temperature coefficient of resonant frequency (τf) and the unloaded quality factor (Q × f) were measured in the microwave frequency region. Two dielectric properties were firstly in the rising tendency and then decreasing with the increased x. On the other hand, a good combination of microwave dielectric properties (εr = 24, Q × f = 23,510 GHz τf = ?9 ppm/°C) were obtained at x = 0.1. The compositions have excellent microwave dielectric properties and hence are suitable for ceramic capacitors or dielectric resonators applications. 相似文献
3.
采用固相反应的方法系统地研究了BZN稳定PZN基陶瓷的相结构与介电性能.随着BZN含量的增加,PZN-BZN陶瓷中钙钛矿相的稳定性增强,居里温度近似呈线性下降,室温介电常数和介质损耗随也显著降低,最小值分别为380和0.002.为获得100%钙钛矿结构的PZN基陶瓷所需BZN的最小用量为8mol%~10mol%,当BZN的mol%超过15mol%时,PZN基陶瓷中钙钛矿相所占的百分比不再受烧结工艺的影响,基本保持100%.1kHz时Pb0.9Ba0.1Zn1/3Nb2/3O3陶瓷的最大介电常数Kmax=8680,tgδ=0.02,相应的居里温度Tm为24℃. 相似文献
4.
《International Journal of Inorganic Materials》2000,2(6):557-560
The hydrothermal synthesis of colorless crystals of Zn(O3PCH3) was achieved using a solution of zinc nitrate and methylphosphonic acid (1:1) in water, in the presence of thiourea. The structure was determined by single crystal X-ray diffraction [monoclinic, space group P21/c (No. 14), a=8.7226(9) Å, b=5.2156(7) Å, c=10.847(1) Å, V=389.48(9) Å3, Z=2]. From this result, the mechanism of the structure modification taking place during the dehydration of Zn(O3PR)–H2O phosphonates was clearly demonstrated. 相似文献
5.
Jianqiang Ma Weibing Ma Qiang Li Xueyuan Meng Benben Niu Yaoxian Guo 《Journal of Materials Science: Materials in Electronics》2014,25(9):3695-3702
Low-temperature sintering of (a–x)Pb(Zr0.48Ti0.52)O3–bPb(Ni1/3Nb2/3) O3–cPb(Zn1/3Nb2/3)O3–xPb(Fe2/3W1/3)O3 (a + b + c + x = 1, 0.06 ≤ x ≤ 0.10) ceramics were prepared through two-step synthesis process using perovskites-structured ferroelectric materials Pb(Fe2/3W1/3)O3 (PFW) as a sintering aid. The effects of PFW content on the densification, microstructure, phase structure, dielectric and piezoelectric properties of the ceramics were investigated. The sintering temperature was reduced from 1,180 °C (without PFW addition) to 940 °C when the material was PFW-doped. PFW-doping increased the sintered density and the average grain size of PFW–PNN–PZN–lead zirconate titanate ceramics. The ceramics sintered at 940 °C for 4 h with x = 0.08 exhibited favorable properties, which were listed as follows: d33 = 496pC/N, εT 33/ε0 = 3,119, tanδ = 2.1 % and Curie temperature = 242 °C. These values indicated that the newly developed composition might be suitable for multilayer piezoelectric devices application. 相似文献
6.
Actinide(VII) salts Rb3[NpO4(OH)2]·3H2O (I) and Rb3[PuO4(OH)2]·3H2O (II) were prepared as single crystals and examined by X-ray diffraction. The compounds are isostructural and crystallize in the monoclinic system, space group C2/c, Z = 4; unit cell parameters: a = 12.1544(3), b = 10.9942(2), c = 7.789(2) ?, ?? = 91.0930(11)° for I and a = 12.1254(3), b = 10.9506(2), c = 7.7699(2) ?, ?? = 90.8253(12)° for II. The main structural elements of I and II are centrosymmetrical anions [AnO4(OH)2]3? forming together with water molecules, owing to strong hydrogen bonding, chains oriented along [101]. In [AnO4(OH)2]3? anions, the central An(VII) atom has a tetragonal-bipyramidal oxygen surrounding. The An-O(OH) interatomic distances decrease in going from I to II owing to actinide contraction by a factor of ??2 more strongly than the An-O bond lengths in the equatorial planes of the bipyramids. The previously studied structure of Cs3[NpO4(OH)2]·3H2O (III) was refined. 相似文献
7.
《Materials Research Bulletin》1987,22(11):1483-1491
Single crystal of [Y(H2O)3]2 (C6Br2O4)3·6H2O and [Y(H2O)3]2 (C6Cl2O4)3·6.6H2O were grown in aqueous silicagel. The compounds are in principle isostructural. In Y chloranilate one additional water site is occupied as verified by X-ray single crystal structure analysis. Y3+ is nine-coordinated by three water molecules and six oxygen atoms of the bischelating (C6X2O4)2− ions (XCl, Br). The coordination polyhedron is an only slightly distorted tri-capped trigonal prism. The connection of Y3+ with the dianions leads to infinite, corrugated layers. The layer stacking yields cage-like cavities in which water molecules are accomodated. Hydrogen bonds interlink adjacent layers. Further hydrogen bonds involve the entrapped water molecules. DSC measurements indicated a complicated dehydration process which caused right at the start destruction of the single crystals. 相似文献
8.
Processing and Properties of Al2O3-ZrO2(3Y)-SiC Nanocomposites 总被引:9,自引:0,他引:9
本文研究了非均相沉淀法制备
Al 相似文献
9.
L. B. Serezhkina A. V. Vologzhanina M. O. Karasev V. N. Serezhkin 《Radiochemistry》2011,53(2):142-145
The compound Cs3[UO2(CH3COO)3]2(NCS)·H2O (I) was synthesized and studied by IR spectroscopy and single crystal X-ray diffraction. Compound I crystallizes in the monoclinic system with the following unit cell parameters: a = 7.8286(9), b = 19.892(2), c = 20.050(2) Å, β = 94.527(2)°, space group P21/c, Z = 4, R = 0.0387. The uranium-containing structural units in crystals of I are mononuclear complexes [UO2(CH3COO)3]? belonging to crystal-chemical group AB 3 01 (A = UO 2 2+ , B01 = CH3COO?) of uranyl complexes. 相似文献
10.
Thirumalai J Chandramohan R Divakar R Mohandas E Sekar M Parameswaran P 《Nanotechnology》2008,19(39):395703
One-dimensional Eu(3+) doped gadolinium oxysulfide (Gd(2)O(2)S:Eu(3+)) nanotubes/nanorods have been synthesized via precursors of Gd(OH)(3) nanostructures using a hydrothermal technique. The blue-shifts in the optical spectra for the Gd(2)O(2)S:Eu(3+) system corresponding to the fundamental absorption and Eu(3+)-X(2-) ligand (X = O/S) charge transfer bands (CTBs) are significant (~0.22-0.36?eV) with respect to the bulk counterpart. The nanotubes are good candidates for investigating the size-induced electrical and optical properties of functional oxysulfides. In order to identify the origin and nature of the electronic transitions observed in the visible region, optical and photo-induced impedance measurements have been extended to the nanotubes in this report. 相似文献
11.
Qi-Long Zhang Hui Yang Jia-Li Zou 《Journal of Materials Science: Materials in Electronics》2009,20(2):181-185
Effects of Li2O–B2O3 on the sintering behavior and the microwave dielectric properties of (Zn0.8Mg0.2)2SiO4–TiO2 ceramics were investigated as a function of Li2O–B2O3 content and sintering temperature. The Li2O–B2O3 combined additives successfully reduced the sintering temperature of (Zn0.8Mg0.2)2SiO4–TiO2 ceramics from 1,250 °C to 900 °C. With the increase of Li2O–B2O3 content, the TiO2 phase decreased and the unknown second phase increased, which led to the dielectric constant (ε
r
) and the maximum Q × f value decrease, and the temperature coefficient of resonant frequency (τ
f
) shift to a negative value. The specimens with 3 wt%Li2O–B2O3 sintered at 900 °C for 2 h showed ε
r
of 8.84, Q × f value of 15,500 GHz, and τ
f
of 17.8 ppm/°C. And the material was compatible with Ag electrodes, which made it a promising ceramic for low temperature
co-fired ceramics technology application. 相似文献
12.
《晶体工程》1999,2(4):251-264
The influence of concentration of water and metal salt in the reaction between Cd(NO3)2·4H2O and 4,4′–bipyridine in MeOH has been studied and three compounds namely, T-shaped [Cd(bpy)1.5(NO3)2]·3H2O, 1 square grid [Cd(bpy)2(H2O)2](NO3)2 4H2O, 2 and one dimensional linear polymer, [Cd(bpy)(H2O)2(NO3)2], 3 were isolated quantitatively in this process. Compound 1 forms in MeOH at high dilution of the metal salt (5.0 mg/mL or less) and for the metal-to-ligand ratio 1:(1.5–2.0). Compound 2 forms exclusively in the concentration range, 17–33% for water in MeOH by volume and 12–28 mg/mL for the metal salt of the solution. Outside these limits, mixtures of 2 and 3 were isolated. For 1:1 ratio of metal salt to bpy, the linear polymer, 3 was obtained in major quantity and its formation was found to be independent of concentration of water or the metal salt. Compounds 1 and 2 have been characterized by X-ray crystallography. On heating all the compounds decompose through a common intermediate [Cd(bpy)(NO3)2] and finally to CdO as monitored by TG. 相似文献
13.
Zhiqiang Li Feng Gao GuoXin Hu Dashuai Zhang Yong Zhang Huajun Sun 《Journal of Materials Science: Materials in Electronics》2014,25(11):5020-5026
Ba(Zn1/3Nb2/3)O3–ZnNb2O6(BZNZ) composite ceramics were fabricated by conventional solid solution processing. After optimizing the composition, the effects of the sintering parameters, such as the heating rate, the soaking time, and the cooling rate on densities, microstructure, and microwave dielectric properties were investigated using orthogonal experimental design method. The results show that with increasing the content of Ba(Zn1/3Nb2/3)O3, the ε r increases, while the Q × f value increases first, then decreases, and τ f shifts to the negative value. The BZNZ ceramics with composition of 0.3Ba(Zn1/3Nb2/3)O3–0.7ZnNb2O6 show the optimal dielectric properties. The results of orthogonal experimental design show that sintering parameters play an important role in the microstructure and dielectric properties. The ceramics show obvious duplex-grain structure. The importance sequence of the sintering parameters is: cooling rate > heating rate > soaking time. The sintering parameters were optimized, with 0.3Ba(Zn1/3Nb2/3)O3–0.7ZnNb2O6 ceramic sintered at a heating rate of 2 °C/min, soaking time of 8 h, and cooling in the air. Samples have the excellent dielectric properties: εr = 32.75, Q × f = 34,100, and τ f = ?10.2 ppm/°C. 相似文献
14.
15.
The (1 − x)Bi(Zn1/2Ti1/2)O3–xPbZrO3 solid solution ceramics were prepared by using solid-state reaction method, and their ferroelectric properties were investigated.
It was found that the perovskite structure is stable for compositions with x ≥ 0.900. Within this composition range, the crystal structure of the solid solution preserves the orthorhombic symmetry of
PbZrO3 (PZ). The Curie point of the ceramics was found to decrease with increasing Bi(Zn1/2Ti1/2)O3 (BZT) content. The intermediate ferroelectric phase of PZ was stabilized by BZT addition and exists within a much wider temperature
range in the solid solution. 相似文献
16.
《材料科学技术学报》2016,(3)
ZnSO_4—Zn(CH_3COO)_2, Zn(NO_3)_2—Zn(CH_3COO)_2, ZnSO_4—Zn(NO_3)_2, ZnSO_4, Zn(NO_3)_2 or Zn(CH_3COO)_2 have been used as zinc sources to prepare ZnS thin films by chemical bath deposition and co-deposition methods.Zn(NO_3)_2 or/and Zn(CH_3COO)_2 is/are favorable for cluster by cluster deposition process while ZnSO_4 favors ion by ion deposition process regardless of concentration ratios of ZnSO_4. However, Zn(NO_3)_2 affects the nucleation density of Zn S nuclei on the substrate. Zn S thin films deposited from ZnSO_4—Zn(CH_3COO)_2 are not only more homogeneous and compact, but also have higher growth rate and adhesion on to the glass substrate. The cubic ZnS films are obtained after only single deposition. The average transmission of films from S6, S7, S8, S9 and S1 for 2 and 2.5 h is greater than 85% in visible region. Compared with the film from S6(112 nm), the film from S7 is not only thicker(125 nm), but also more transparent. The band gaps of the films deposited from S6, S7, S8, S9 and S1 for 2 and 2.5 h range from 3.88 to 3.98 e V.The effects of anions from different zinc salts are discussed in detail. 相似文献
17.
The piezoelectric properties of Pb(In(0.5)Nb(0.5))O(3)-Pb(Mg(1∕3)Nb(2∕3))O(3)-PbTiO(3) crystals with various engineered domain configurations were investigated. Rhombohedral and monoclinic∕orthorhombic crystals poled along their crystallographic [011] directions were found to possess macroscopic mm2 symmetry, with "2R" and "1O" domain, respectively. Crystals with the "2R" domain configuration were found to exhibit high extensional piezoelectric coefficients d(33) (~1300 pC∕N) and d(32) (~-1680 pC∕N), while crystals with the "1O" configuration possessed high shear coefficients d(15) (~3500 pC∕N) and d(24) (~2070 pC∕N), with relatively low extensional piezoelectric coefficients d(33) (~340 pC∕N) and d(32) (~-260 pC∕N). The observed results were explained by "polarization rotation" model, as related to their respective domain configurations. 相似文献
18.
A new Am(V) chromate complex with outer-sphere cesium cation, Cs3AmO2(Cr2O7)2·H2O, was prepared from aqueous solution. Its composition and structure were determined by single crystal X-ray diffraction. The Am(V) atom has coordination surrounding in the form of a distorted pentagonal bipyramid with the O atoms of the AmO 2 + group in apical positions. The equator of the bipyramid is formed by the O atoms of four dichromate groups and of the water molecule. The mean bond lengths (Å) are as follows: Am=O 1.802(5), Am-O(Cr2O7) 2.443(6), and Am-Ow 2.519(6). The Am(V) pentagonal bipyramids are combined via bidentate bridging Cr2O 7 2? anions into infinite chains [AmO2(Cr2O7)2H2O] n 3? arranged in layers parallel to the series of diagonal planes (111). A system of hydrogen bonds links the chains in a layer and the layers with each other. The Cs cations are arranged between the layers, forming cationic interlayers. 相似文献
19.
Zn—Al2O3和Zn—SiO2复合镀层的研制 总被引:4,自引:0,他引:4
详细叙述了Zn-Al2O3和Zn-SiO2复合镀层的制做方法,提出了复合镀液中所用微粒子和净化处理方法。对复合镀层的耐腐蚀性和结合力进行了测定,得出了耐腐蚀性和结合力均较好的Zn-Al2O3和Zn-SiO2复合镀层中粒子的含量范围等有用的数据。 相似文献
20.
Liu Fei Cheng Li-jin Li Hao Liu Shao-jun 《Journal of Materials Science: Materials in Electronics》2021,32(21):26126-26136
Journal of Materials Science: Materials in Electronics - The miniaturization of microwave and/or radio frequency devices and equipment has been driving the development of dielectric ceramics in... 相似文献