ZrO2及ZrO2:CdS薄膜的制备和表征

利用ｓｏｌ－ｇｅｌ方法合成了ＺｒＯ_２薄膜,并通过在ＺｒＯ_２薄膜中复合ＣｄＳ纳米粒子成功地制备了ＺｒＯ_２：ＣｄＳ薄膜．制得的ＺｒＯ_２薄膜透明并具有较好的光透射性,而ＺｒＯ_２的含量及膜厚是影响其光透射性的主要因素．分散在ＺｒＯ_２：ＣｄＳ薄膜中的ＣｄＳ纳米粒子为六方相结构,并具有较好的分散性,其平均尺寸为４～６ｎｍ．实验结果表明：ＺｒＯ_２颗粒的晶化会对薄膜的光学性能及表面形貌产生影响,但ＣｄＳ的形成可以抑制薄膜表面ＺｒＯ_２颗粒的晶化,从而得到较为平滑的薄膜．     

Synthesis,structural and optical characterizations of ZrO2-bromothymol blue nanocomposite thin-film [ZrO2+BTB]C and its application: experimental and TDD-DFT computations

Journal of Materials Science: Materials in Electronics - A [ZrO2+BTB]C nanocomposite was synthesized and prepared as a thin film using the sol–gel spin coating...     

ZrO2和ZrO2:Dy3+纳米晶发光特性

采用液相沉淀法制备了不同掺杂浓度和尺寸的ZrO2和ZrO2:Dy纳米晶,研究了其发光特性.结果表明在纳米ZrO₂中,存在着宽带激发和发射,起源为电子在价带和导带之间的跃迁.在Dy³⁺掺杂的样品中,随着颗粒尺寸的长大,其发光增强.并且共掺杂Li⁺的样品发光强度被极大地提高.随着Dy³⁺浓度的变化,黄发射和蓝发射的强度比(Y/B)发生改变,且浓度猝灭是通过近邻激活剂间的交换作用进行的.     

Enhanced electrochemical performance of Li-rich manganese layered oxide Li1.2Mn0.54Ni0.13Co0.13O2 by surface modification with Al2O3–ZrO2 for lithium-ion battery

Journal of Materials Science: Materials in Electronics - In this work, the Li-rich manganese layered oxide Li1.2Mn0.54Ni0.13Co0.13O2 (LMNC in short) is coated with a novel Al2O3–ZrO2 layer...     

Current transfer processes in a hydrated layer localized in a two-layer porous structure of nanosized ZrO2

Journal of Materials Science: Materials in Electronics - The current transfer through a two-layer structure saturated with absorbed water, each layer of which consists of pressed ZrO2 nanoparticles...     

PET接枝改性纳米ZrO2/PC复合材料的力学性能

采用接枝聚合反应在纳米ZrO₂表面接枝聚对苯二甲酸乙二醇酯 (PET) 低聚物,以提高其与聚碳酸酯(PC)的相容性;改性纳米ZrO₂与PC经过共混挤出,制备了纳米ZrO₂/PC复合材料。采用FTIR、XPS、TEM、TG、接触角等测试方法对接枝改性后的纳米ZrO₂进行了表征,结果表明,PET化学键合到了纳米ZrO₂表面,使ZrO₂疏水性显著增强,微观颗粒分散性好。对纳米ZrO₂/PC复合材料进行了力学性能测试,探讨了纳米ZrO₂的添加量与复合材料力学性能的关系。结果表明：纳米ZrO₂/PC复合材料的力学性能较纯PC有明显改善;随着改性纳米ZrO₂含量的增加,缺口冲击强度和拉伸强度都呈现出先增加后降低的趋势,分别在ZrO₂质量分数为1%和0.3%时达到最大值;弯曲强度在实验范围内一直呈上升趋势,最大弯曲强度比纯PC提高2.54 MPa。     

Thermodynamic Assessment of the ZrO2—CeO2 and ZrO2—CeO1.5 Binary System

An optimal set of thermodynamic parameters of the ZrO2-CeO1.5 system has been obtained using phase diagram data by modern CALPHAD (CAL culation of PHAse Diagrams) technique.The liquid and other solid solution phases were regarded as substitutional solution.The ordered ZrCe2O7 phase was treated as a stoichiometric compound.The ZrO2-CeO2 system has been re-optimized with new reference state.A comparison between the ZrO2-CeO2 system and ZrO2-CeO1.5 system has been made through calculation.With the calculation, the experimental information is well reproduced and a good agreement is obtained.     

Influence of Reducing Media on the Structure and Physicomechanical Properties of Ceramics of the ZrO2–Y2O3–Al2O3–NiO – CuO System

Materials Science - We study the regularities of changes in the microstructure, strength, electric conductivity, and micromechanism of fracture of 50% (ZrO2–8 mole% Y2O3–2 wt.% Al2O3) +...     

Influence of the Working Media of Fuel Cells on the Structure and Physicomechanical Characteristics of Ceramics of the ZrO2–Y2O3–NiO System

Materials Science - We study the properties of ZrO2 –Y2O3 –NiO ceramics obtained by using the technologies of sintering of powders and tape casting in the intact state and after...     

Subsolidus phase relationships in the ZrO2-rich part of the ZrO2–Zr3N4 system

Zirconia can be stabilized by incorporation of nitrogen. The phase relationships in the ZrO2-rich part of the system ZrO2–Zr3N4 have been investigated using high-temperature X-ray methods. At temperatures above 1000°C, a tetragonal and a cubic phase with randomly distributed vacancies exists, depending on the amount of incorporated nitrogen. This high-temperature behaviour is similar to that of systems like ZrO2–Y2O3, which is another indication for the important role of anion vacancies in zirconia systems. Below 1000°C, β-type phases with an ordered arrangement of anion vacancies are stable. This revised version was published online in November 2006 with corrections to the Cover Date.     

Y2O3添加剂对ZrO2超微粉体性质的影响

添加0-6mol%Y2O3的ZrO2超微粉体由化学共沉淀法制备，系统地研究了添加剂对粉体粒子粒径，表面性质和团聚状态的影响，结果表明，添加Y2O3组元，使制备的ZrO2粉体粒子粒径减小，对粒子的长大趋势可起到抑制作用，但加剧了粉体粒子的团聚，团聚体颗粒变大，团聚强度升高，随着组元添加量的增多，作用加剧。     

Electrical Properties of Sputter-deposited ZrO2-based Pt/ZrO2/Si Capacitors

Pt/ZrO2/Si sandwich structures where ZrO2 is deposited by radio frequency （r.f.） magnetron sputtering using a Zr target in an atmosphere of O2/Ar gas mixture, were fabricated and the effects of the O2/Ar flow ratio in the reactive sputtering process, the annealing temperature, the ZrO2 film thickness on the structure, the surface roughness of ZrO2 films and the electric properties of Pt/ZrO2/Si metal-oxide-semiconductor （MOS） capacitors were investigated. The optimum process parameters of the Pt/ZrO2/Si capacitor based on reactively sputtered-ZrO2 determined in such a way as the capacitance is maximized and the leakage current, the oxide charge, and the interface trap density are minimized that is the O2/Ar flow ratio of 1.5, the annealing temperature of 800℃, and the film thickness of 10 nm. Also the conduction mechanism in the Pt/ZrO2/Si capacitor has been discussed.     

Nano ZrO2 Particulate-reinforced Lead-Free Solder Composite

A lead-free solder composite was prepared by adding ZrO2 nanopowders in eutectic Sn-Ag alloy. Microstrucrural features and microhardness properties of those solders with different ZrO2 nanopowder fraction were examined. Results indicate that the addition of ZrO2 nanopowders reduced the size of β-Sn grains and restrained the formation of bulk Ag3Sn intermetallic compounds （IMCs） due to the adsorption effect of the ZrO2 particles. The Vicker＇s hardness of the obtained lead-free solder composites fits well with the HalI-Petch relationship. The refinement of β-Sn grains favors to improve the microhardness of composite solders.     

ZrO2:CdS薄膜的光物理性质

利用吸收和荧光光谱研究了ＺｒＯ_２：ＣｄＳ薄膜的光物理特性．实验观察到了随颗粒尺寸的减小ＣｄＳ的吸收带边的蓝移现象．研究了不同激发条件下的荧光光谱,发现了薄膜中ＣｄＳ的微弱的荧光发射．并且分析了介质效应对ＣｄＳ光学特性的影响．     

Characteristics of nanocomposite ZrO2/Al2O3 films deposited by plasma-enhanced atomic layer deposition

Nanocomposite ZrO2/Al2O3 (ZAO) films were deposited on Si by plasma-enhanced atomic layer deposition and the film characteristics including interfacial oxide formation, dielectric constant (k), and electrical breakdown strength were investigated without post-annealing process. In both the mixed and nano-laminated ZAO films, the thickness of the interfacial oxide layer (T(IL)) was considerably reduced compared to ZrO2 and Al2O3 films. The T(IL) was 0.8 nm in nano-composite films prepared at a mixing ratio (ZrO2:Al2O3) of 1:1. The breakdown strength and the leakage current level were greatly improved by adding Al2O3 as little as 7.9% compared to that of ZrO2 and were enhanced more with increasing content of Al2O3. The k of ZrO2 and mixed ZAO (Al2O3 7.9%) films were 20.0 and 16.5, respectively. These results indicate that the addition of Al2O3 to ZrO2 greatly improves the electrical properties with less cost of k compared to the addition of SiO2.     

Ultrasonic through-transmission method of evaluating the modulus of elasticity of Al2O3–ZrO2 composite

The elastic properties of Al2O3–ZrO2 composite were determined from ultrasonic velocity measurements, and were found to be dependent upon the amount of ZrO2 phase, the compacting pressure of the green ceramic and sintering time. The velocity in the Al2O3–ZrO2 composite increased to a maximum for about 3 wt% unstabilized ZrO2 dispersed in Al2O3. The velocity decreased monotonically thereafter. The increase in moduli, as shown by an increase in velocity, has been attributed to phase transformation of the unstabilized ZrO2 from tetragonal to a monoclinic phase, which presumably leads to a toughening and strengthening effect, and also due to the action of ZrO2 in stopping grain growth of Al2O3 during densification. The excessive shear strain, induced by the tetragonal→monoclinic transformation phase, with greater than 50 wt% ZrO2 content, caused microcracks to appear in the composite. This reduced the elastic moduli of the composite. It was found that the composition dependence of the elastic moduli lie outside the theoretical bound of Voigt and Reuss for the elastic moduli of two-phase materials, and that by increasing the compacting pressure, an improvement in the elastic moduli of the sintered composite occurred irrespective of ZrO2 content. The thermal expansion of the composites showed no appreciable change with addition of zirconia up to 5 wt% ZrO2. However, dimensional changes due to phase transformation particularly with high zirconia content have been established. This revised version was published online in November 2006 with corrections to the Cover Date.     

微波法制备ZrO2/Al2O3复合载体及其性能的研究

采用真空浸溃和微波技术在经过扩孔处理的Al2O3载体上制备ZrO2/Al2O3复合载体.经XRD、DSC-TG、TPD等测试表明:ZrO2能单层分散在Al2O3表面,分散阈值为0.242gZrO2/gAl2O3;在微波条件下,ZrO2的单层分散没有明显改变Al2O3的孔径分布,复合载体具有较好的热稳定性,ZrO2单层分散的复合载体表面具有酸、碱性质,碱性中心数大于非单层分散的复合载体,同时单层分散的复合载体具有较大的比表面积和适宜的孔径分布.初步证明,Al2O3能诱导单层分散ZrO2产生新的碱性中心.     

Thermo dynamic Assessment and Microstructure of the ZrO_2-CeO_2-Al_2O_3 System

The ZrO2-CeO2-AI2O3 system has been assessed with the CALPHAD (Calculation of Phase Diagrams) technique using the PARROT procedure. The experimental information on the ZrO2-AI2O3, AI2O3-CeO2 systems as well as the isothermal sections of the ternary system at 1673 K and 1873 K is well reproduced. According to the assessed isothermal section at 1723 K, no alumina dissolves into the tetragonal zirconia phase. Specimens with different alumina content are fabricated from commercial 12 mol pct CeO2-stabilized ZrO2 powder (12Ce-ZrO2). The thermodynamic properties are consistent with the observed microstructure, which present a combination of tetragonal phase and alumina grains.     

基于高温熔凝法Al_2O_3/ZrO_2/YAG共晶陶瓷显微组织演变规律

作为超高温结构材料,共晶氧化物陶瓷的力学性能和显微组织密切相关。采用高温熔凝法制备Al_2O_3/ZrO_2/YAG共晶陶瓷体,研究熔体温度和结晶种子对凝固组织影响规律,运用经典形核机制和Jackson-Hunt共晶生长模型探讨了凝固组织的演变机理。研究表明,随着熔体温度升高(1750~2000℃),凝固体物相组成从α-Al_2O_3,c-ZrO_2和YAG转变为α-Al_2O_3,c-ZrO_2和亚稳相YAP。凝固组织依次经历:非共晶Al_2O_3/ZrO_2/YAG、不规则共晶Al_2O_3/ZrO_2/YAG、纳米纤维状共晶Al_2O_3/ZrO_2/YAG和复杂粗大的亚稳复合陶瓷Al_2O_3/ZrO_2/YAP。分析表明,凝固组织的演变源于异质晶核点不断钝化导致形核过冷度和凝固路径改变,所以合理选择熔体温度和结晶种子是共晶组织调控的关键。     

ZrO2-Si3N4陶瓷复合材料中的化学不相容性

ＺｒＯ_２与Ｓｉ_３Ｎ_４之间存在化学反应生成ＺｒＮ或氧氮化锆,ＺｒＯ_２也可能被氮稳定形成氨稳定的ＺｒＯ_２本文对ＺｒＯ_２－Ｓｉ_３Ｎ_４陶瓷复合材料中的化学不相容性及抑制措施进行了综述．