Optimized growth and dielectric properties of barium titanate thin films on polycrystalline Ni foils

Barium titanate(BTO) thin films were deposited on polycrystalline Ni foils by using the polymer assisted deposition(PAD) technique.The growth conditions including ambient and annealing temperatures were carefully optimized based on thermal dynamic analysis to control the oxidation processing and interdiffusion.Crystal structures,surface morphologies,and dielectric performance were examined and compared for BTO thin films annealed under different temperatures.Correlations between the fabrication conditions,microstructures,and dielectric properties were discussed.BTO thin films fabricated under the optimized conditions show good crystalline structure and promising dielectric properties with εr～ 400 and tan δ < 0.025 at 100 kHz.The data demonstrate that BTO films grown on polycrystalline Ni substrates by PAD are promising in device applications.     

一道面积问题的推广

存最近一次数学课外兴趣小组的活动中，我们碰到这样一道问题：     

Enhancing the thermal conductivity of polymer-assisted deposited Al2O3 film by nitrogen doping

<正>Polymer-assisted deposition technique has been used to deposit Al₂O₃ and N-doped Al₂O₃（AlON） thin films on Si（100） substrates.The chemical compositions,crystallinity,and thermal conductivity of the as-grown films have been characterized by X-ray photoelectron spectroscopy（XPS）,X-ray diffraction（XRD）,and 3-omega method,respectively. Amorphous and polycrystalline Al₂O₃ and AlON thin films have been formed at 700℃and 1000℃.The thermal conductivity results indicated that the effect of nitrogen doping on the thermal conductivity is determined by the competition of the increase of Al-N bonding and the suppression of crystallinity.A 67%enhancement in thermal conductivity has been achieved for the samples grown at 700℃,demonstrating that the nitrogen doping is an effective way to improve the thermal performance of polymer-assisted-deposited Al₂O₃ thin films at a relatively low growth temperature.     

大气颗粒物中重金属生态风险评价与源解析

用电感耦合等离子体发射光谱法（ICP-OES）分析厦门市大气TSP中重金属含量,研究大气重金属生态风险和来源。结果表明,各功能区大气TSP日均质量浓度范围为192-326μg/m3;TSP中各重金属含量空间分布差异较大,含量由高到低分别为：工业区,交通区,居住区。富集因子显示,Cd和As在3个功能区的富集程度极高,Cu在3个功能区也有不同程度的富集,Sr和Mg在居住区和交通区存在一定程度的富集。潜在生态风险评价表明,重金属潜在生态风险程度由高到低的顺序为：Cd,As,Cu,Pb,Co,Ni,Cr,V,Mn,Ti,三个功能区综合潜在生态风险程度极高,由高到低顺序为：居住区,交通区,工业区。多元统计分析结果表明,重金属主要来源于自然和人为扬尘、工业活动以及交通和燃烧排放,贡献率分别为43.56%、26.19%和17.12%。     

可延展柔性无机微纳电子器件原理与研究进展

为适应下一代电子产品便携性、形状可变性、人体适用性等方面的进一步需求,近年来基于无机电子材料的可延展柔性电子技术成为全球电子产业界与学术界关注的新焦点.与有机柔性电子学器件不同,可延展柔性无机电子器件指的是建立在柔性基底上的无机电子组件.这种具有柔性的集成电路利用力学设计提供大变形,在保持无机脆性电子器件高性能和高可靠性的同时,具备形状可弯曲、可伸缩等柔性性能.本文综述了近年来无机柔性电子器件的进展,包括力学设计原理、基于界面黏附的转印集成方法以及柔性大变形下的失效机理等,并展望了未来的应用和发展.     

掺Gd3+钼酸盐AMoO4 (A=Ca,Sr, Ba,Pb)自旋哈密顿参量的理论计算

采用基于单电子晶体场机制的对角化能量矩阵方法, 计算了Gd³⁺在钼酸盐AMoO₄ (A=Ca, Sr, Ba, Pb)晶体中的自旋哈密顿参量(g因子g_//, g_⊥和零场分裂b₂⁰, b₄⁰, b₄⁴, b₆⁰, b₆⁴). 矩阵中的晶体场参量采用重叠模型计算. 计算结果显示, 应用三个合理的可调参量[即重叠模型中的内禀参量A₂ (R₀), A₄ (R₀)和A₆ (R₀)], 计算的七个自旋哈密顿参量与实验结果符合甚好, 表明该方法可用于计算或解释Gd³⁺在晶体中的自旋哈密顿参量. 关键词： AMoO₄ (A=Ca,Sr,Ba,Pb):Gd³⁺晶体')" href="#">AMoO₄ (A=Ca,Sr,Ba,Pb):Gd³⁺晶体 自旋哈密顿参量 晶体场理论 对角化能量矩阵     

PbZr0.53Ti0.47O3/SiO2/Si复合薄膜的取向生长及铁电性研究

利用超薄的ＳｉＯ２做缓冲层,用脉冲激光沉积法在Ｓｉ（１００）上制备了具有良好铁电性的高度（１００）取向的ＰＺＴ薄膜．通过对不同条件下在ＳｉＯ２／Ｓｉ（１００）上生长的ＰＺＴ薄膜的研究,分析了ＳｉＯ２厚度、沉积温度、退火时间对ＰＺＴ性能的影响