以Al2O3为过渡层脉冲激光法制备PZT铁电薄膜

为实现PZT铁电薄膜与半导体衬底的直接集成引入Al2O3为过渡层，首先用真空电子束蒸发法在Si(100)，多昌金刚石（111）衬底上生长约20nm厚的Al2O3过渡层，接着在上述衬底上采用脉冲激光淀积（PLD）法淀积PZT薄膜，衬底温度为350-550℃。X光电子能谱（XPS）测试表明，在高真空下，电子束蒸发Al2O3固态源能获得化学配比接近蒸发源的Al2O3薄膜。X射线衍射（XRD）测试说明，不论衬底是硅还是多晶金刚石，当衬底温度为550℃时，PZT在Al2O3过渡层上呈现（222）取向的焦绿石相结构，当衬底是金刚石时，通过如下工艺：（1）较低温度（350℃）淀积；（2）空气氛围650℃快速退火5min，可以在Al2O3过渡层上获得高度（101）取向的钙钛矿结构的铁电相PZT薄膜，最后AFM测试显示，在硅衬底上，PZT薄膜的表面均方根粗糙度为9.78nm；而在多晶金刚石衬底上，PZT薄膜的表面均方根粗糙度为17.2nm。     

等离子体源增强磁控溅射沉积Al2O3薄膜研究

采用电子回旋共振微波等离子体源增强磁控溅射沉积氧化铝薄膜。X射线光电子谱和X射线衍射分析表明，在600℃沉积温度下，Si（100）基片上获得了亚稳的具有化学计量配比成分、面心立方结构的γ－Al2O3薄膜。薄膜的折射率为1．7，与稳定的α－Al2O3体材料相当。     

射频磁控溅射法制备Al2(WO4)3薄膜和负热膨胀性能研究

采用WO3和Al2O3陶瓷靶材,以双靶交替射频磁控溅射法,在石英基片上沉积制备了Al2（WO4）3薄膜。利用X射线衍射仪（XRD）、扫描电子显微镜（SEM）,研究了退火温度对Al2（WO4）3薄膜的相组成和表面形貌的影响,采用表面粗糙轮廓仪和划痕仪测量薄膜厚度,探索了薄膜的制备工艺以及薄膜与基片的结合力,采用高温X射线衍射和晶胞参数指标化软件,初步研究了薄膜热膨胀特性。实验结果表明：磁控溅射沉积制备的这种薄膜为非晶态,表面平滑、致密,随着热处理温度的升高,薄膜开始结晶且膜层颗粒增大,在950℃热处理10min后得到Al2（WO4）3薄膜,薄膜与基片的结合力为13．6N,薄膜物质热膨胀特性呈各向异性。     

MnV2O6纳米片的简易水热合成

以醋酸为酸化剂，Mn（CH3COO）2·4H2O和NH4VO3为原料，在180℃反应18h，经水热制备了MnV2O6纳米片．利用X射线衍射（XRD）、场发射扫描电镜（FESEM），透射电子显微镜（TEM）和X射线光电子能谱（XPS）对产物进行了表征，该产物由宽约0．85μm，长度约1．7μm，厚度平均为100nm的纳米片构成．     

非晶含氟聚合物薄膜的热稳定性

以TefonAF1600为原料，用旋涂法制备了非晶含氟聚合物（AF）薄膜，通过扫描电镜（SEM），傅立叶转换红外（FTIR）光谱和X射线光电子（XPS）光谱等手段对热退火前后的薄膜进行了表征，所得薄膜具有无针孔，较光滑和平整的表面，300℃退火后薄膜表面的均匀性进一步改善，AF薄膜的300℃以下具有良好的热稳定性，在400℃退火后CF3吸收峰强度稍有降低，在400℃退火后，其所含的CF3键合构型显著降低，CF2，CF等其它构型没有明显的变化，由于CF3基团的分解有少量无定型碳生成。     

激光刻蚀工艺对Al2O3-ZrO2固溶度和结晶度的影响

利用X射线衍射，X射线吸收精细结构谱和高分辨电镜研究了激光刻蚀工艺对Al2O3-ZrO2固溶度和结晶度的影响．结果表明，Al2O3在ZrO2中的固溶度越大，ZrO2晶体结构无序度越大．样品室的空气压力越大，粉体中无定形相的含量越大．无定形ZrO2中存在短程有序-长程无序结构Zr-O-Zr（Al）．同Al2O3-ZrO2固溶体相比，无定形ZrO2具有更短的Zr-O和Zr-Zr（Al）原子间距离和更大的无序度．     

Al/MoO3和Al/Fe2O3纳米含能薄膜制备与性能表征

使用自动控制磁控溅射仪制备纳米级Al/MoO3和Al/Fe2O3含能薄膜,使用扫描电镜(SEM)、原子力显微镜(AFM)对其形貌进行分析,使用X射线衍射(XRD)、X射线光电子能谱(XPS)分析薄膜组分,利用差示扫描量热(DSC)进行热力学分析。分析显示,含能薄膜结构完整,层状结构清晰;Al/MoO3纳米薄膜中MoO3有较大部分被还原为Mo2O5和MoO2,Al/Fe2O3纳米薄膜中Fe2O3有部分被还原为FeO,含能薄膜中Al有少部分被氧化为非晶结构的Al2O3。含能薄膜放热峰起始温度较低,活化能较小,反应活性较高,放热量较大,分别为3198和1680J/g。     

掺杂氧化铝对金红石相纳米TiO2微结构和光催化活性的影响

为降低金红石相纳米TiO2的光催化活性，利用氧化铝对其进行高温掺杂处理．利用X射线衍射、X射线光电子能谱、透射电镜和比表面仪对纳米TiO2进行了表征．结果表明，最佳的煅烧温度是800℃，最佳的氧化铝用量是m（Al2O3）：m（TiO2）=1：5．氧化铝的掺杂抑制了纳米TiO2的粒径和晶粒长大．随着m（Al2O3）：m（TiO2）的增大，纳米TiO2的粒径和晶粒尺寸逐渐减少，比表面积和孔容逐渐增大．从电子结合能和晶胞参数的变化可以推测高温煅烧可使Al^3＋掺杂到纳米TiO2的晶格中．氧化铝的饱和掺杂量约为m（Al2O3）：m（TiO2）=1：20，当m（Al2O3）：m（TiO2）≥1：10时，出现了晶态氧化铝的结构．     

等离子增强化学气相淀积硅化钛薄膜的特性

本文以四氯化钛（ＴｉＣｌ４）和硅烷（ＳｉＨ４）为源物质，采用等离子增强化学气相淀积（ＰＥＣＶＤ）工艺结合常规热退火制备了优良的ＴｉＳｉ２薄膜。研究了淀积和退火条件对薄膜性质的影响。用四探针检测了退火前后薄膜的薄层电阻，用俄歇电子能谱（ＡＥＳ）和Ｘ射线衍射分析了薄膜的化学组成和晶体结构。     

PECVD法淀积氟碳掺杂的氧化硅薄膜表征

以正硅酸乙酯（ＴＥＯＳ）和八氟环丁烷（Ｃ４Ｆ８）为原料,采用等离子体增强化学气相淀积（ＰＥＣＶＤ）方法制备了氟碳掺杂的氧化硅薄膜（ＳｉＣＯＦ）．样品的Ｘ射线光电子能谱（ＸＰＳ）和傅立叶变换红外光谱（ＦＴＩＲ）分析表明薄膜中含有Ｓｉ－Ｆ、Ｓｉ－Ｏ、Ｃ－Ｆ、Ｃ－ＣＦ_ｘ、ＣＦ₂等构型．刚淀积的薄膜的折射率约为１．４０．对暴露在空气中以及在不同温度下退火后薄膜的折射率做了测量,并对其变化机理进行了讨论,同时表明了理想的淀积温度应是３００℃．     

Magnetic coupling in La0.67Ca0.33MnO3/La0.67Sr0.33CoO3/La0.67Ca0.33MnO3 sandwiches

La_0.67Ca_0.33MnO₃ (LCMO)/La_0.67Sr_0.33CoO₃ (LSCO)/LCMO trilayer films are fabricated on single-crystal substrates NdGaO₃ (110) and the interlayer coupling are investigated. Compared with LCMO single layer, sandwiches showed the enhanced metal-insulator transition temperature of LCMO layers. The magnetoresistance is dependent on spacer thickness and the peak value dramatically decreases when LSCO layer is thick enough because of shorting by the LSCO layer. The magnetic coercivity H_C shows a nonmonotonic behavior with changing spacer layer thickness and the waist-like hysteresis indicates that there is an indirect exchange coupling between the top and bottom LCMO layers across the spacer layer.     

Varistor properties of ZnO-Pr6O11-CoO-Cr2O3-Y2O3-In2O3 ceramics

The varistor properties of the ZnO-Pr₆O₁₁-CoO-Cr₂O₃-Y₂O₃-In₂O₃ ceramics were investigated for different concentrations of In₂O₃. The increase of In₂O₃ concentration slightly increased the sintered density (5.60-5.63 g/cm³) and slightly decreased the average grain size (3.4-2.9 μm). The breakdown field increased from 6023 to 14822 V/cm with increasing concentration of In₂O₃. The nonlinear coefficient increased from 17.6 to 44.6 for up to 0.005 mol%, whereas the further doping caused it to decrease to 36.8. In₂O₃ acted as an acceptor due to the donor concentration, which decreases in the range of 1.02 × 10¹⁷ to 0.24 × 10¹⁷/cm³ with increasing concentration of In₂O₃.     

Nanocrystallization of SrBi2Nb2O9 from glasses in the system Li2B4O7---SrO---Bi2O3---Nb2O5

Transparent glasses in the system (100−x)Li₂B₄O₇–x(SrO---Bi₂O₃---Nb₂O₅) (10≤x≤60) (in molar ratio) were fabricated by a conventional melt-quenching technique. Amorphous and glassy characteristics of the as-quenched samples were established via X-ray powder diffraction (XRD) and differential thermal analyses (DTA) respectively. Glass–ceramics embedded with strontium bismuth niobate, SrBi₂Nb₂O₉ (SBN) nanocrystals were produced by heat-treating the as-quenched glasses at temperatures higher than 500 °C. Perovskite SBN phase formation through an intermediate fluorite phase in the glass matrix was confirmed by XRD and transmission electron microscopy (TEM). Infrared and Raman spectroscopic studies corroborate the observation of fluorite phase formation. The dielectric constant (_r) and the loss factor (D) for the lithium borate, Li₂B₄O₇ (LBO) glass comprising randomly oriented SBN nanocrystals were determined and compared with those predicted based on the various dielectric mixture rule formalism. The dielectric constant was found to increase with increasing SBN content in LBO glass matrix.     

Microstructures of YBa2Cu3O7/La0.7Ca0.3MnO3 and La0.7Ca0.3MnO3/YBa2Cu3O7 bi-layers grown on (001)LaAlO3

Epitaxial YBa₂Cu₃O₇/La_0.7Ca_0.3MnO₃ (YBCO/LCMO) bi-layers and La_0.7Ca_0.3MnO₃/YBa₂Cu₃O₇ (LCMO/YBCO) bi-layers were grown on (001)LaAlO₃ by pulsed laser deposition, and their microstructures were compared by transmission electron microscopy investigation. In the YBCO(100 nm)/LCMO(150 nm) bi-layers, the LCMO layer consists of columnar grains of ~ 17 nm in diameter and contains mixed orientation domains of [100]_c, [010]_c and [001]_c. The YBCO layer is totally c-axis oriented and the YBCO lattices are tilted − 2.5° to + 2.5° as they grew on the rough surfaces of LCMO columnar grains. For the LCMO(140 nm)/YBCO(140 nm) bi-layers, the LCMO/YBCO interface is sharp and flat. The initial 12-nm thickness of the YBCO layer is composed of c-axis oriented domains, and the upper part of YBCO layer is [100] oriented. The LCMO layer was predominantly [001]_c oriented while [100]_c-oriented domains were occasionally observed.     

Syntheses of hollandite type Rb2Cr8O16, K2Cr2V6O16 and K2V8O16

Hollandite-type compounds, Rb₂Cr₈O₁₆, K₂Cr₂V₆O₁₆ and K₂V₈O₁₆, were synthesized under high P-T conditions up to 1200°C and 7GPa. The structural refinement using a single crystal of Rb₂Cr₈O₁₆ confirms that the structure is similar to that of K₂Cr₈O₁₆. Magnetic measurements indicate that Rb₂Cr₈O₁₆ is ferromagnetic below 295K, K₂Cr₂V₆O₁₆ paramagnetic down to 77K and K₂V₈O₁₆ has susceptibility anomaly at 175K. These compounds are all semiconductive and show discontinuities in temperature-resistivity curves at points corresponding to magnetic anomalies.     

Vapour-liquid equilibria in the ternary mixtures N2---CH4---C2H6 and N2---C2H6---C3H8

A systematic study was performed with mixtures consisting of N₂, CH₄, C₂H₆ and C₃H₈, to investigate experimentally phase equilibria and caloric properties and to test the accuracy of thermodynamic correlations. The first part of this Paper reports results of T---p---x---y measurements on ternary systems in the range 20 < p < 120 bar and 140 < T < 220 K. The results are compared with data calculated by generalized equations of state.     

PbSbBiS4-Sb2S3 and PbSbBiS4-Bi2S3 joins in the PbS-Sb2S3-Bi2S3 system

Phase equilibria along the PbSbBiS₄-Sb₂S₃ and PbSbBiS₄-Bi₂S₃ joins of the PbS-Sb₂S₃-Bi₂S₃ system have been studied for the first time using differential thermal analysis, X-ray diffraction, microstructural analysis, microhardness tests, and density measurements, and the phase diagrams of the joins have been mapped out. The joins are shown to be pseudobinary with limited series of terminal solid solutions. The solid solutions are p-type semiconductors.     

Characterization of YBa2Cu3O7/PrBa2Cu3O7 superlattices

We investigated the structural and superconducting properties ofc-axis oriented (YBa₂Cu₃O₇) _nY /(PrBa₂Cu₃O₇) _npr superlattices with thicknesses of the individual layers down to one unit cell (10nY1; 18>nPr 1). By transmission electron microscopy and X-ray diffraction we find an excellent structural quality of the samples, though the quantitative analysis shows the existence of defects. In superlattices with decoupled YBa₂Cu₃O₇ layers of two unit cell thickness we find a highT _c value of 75 K. We probed the flux line structure in the superlattices by measurements of the critical current density in magnetic fields. The experiments show that the flux-line dynamics is dominated by the movement of pancake vortices.     

Structural study of Sr0.3Ba0.7Nb2O6 and La0.030Sr0.255Ba0.700Nb2O6 ceramic systems

Sr_0.3Ba_0.7Nb₂O₆ (SBN) and La_0.030Sr_0.255Ba_0.700Nb₂O₆ (LSBN) ceramic compounds have been prepared using the traditional ceramic method at two different calcination temperatures (900 and 1000 °C) and later sintered both at 1400 °C. A study of the effects of the calcination temperatures and La substitution on the morphological, compositional, and structural properties of SBN and LSBN is presented using scanning electronic microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction (XRD) analysis. From Rietveld refinement processes, the XRD patterns were interpreted to evaluate such effects in the structural parameters and the site occupation factors of the heavy metals and oxygen atoms. The effect of the incorporation of La resulted in a 0.25% cell contraction and turned out to be higher than the 0.08% dilation effect produced by the increase of calcination temperature. The La ion with similar effective ionic radius and higher electronegativity is incorporated into the structure occupying the A₁ site just like the Sr ions in the SBN compound. Differences in the site occupation factors between the SBN and LSBN samples lead to substantial changes in the physical properties such as temperature of relative dielectric constant maximum, relative dielectric constant, and dielectric loss, correlated with the distortion and the relative orientation of the oxygen octahedra.     

The effect of Bi1.5Zn0.5Nb0.5Ti1.5O7 cover layer on the dielectric and tunable properties of Ba0.6Sr0.4TiO3/Bi1.5Zn0.5Nb0.5Ti1.5O7 bilayered thin films

Bi_1.5Zn_0.5Nb_0.5Ti_1.5O₇ (BZNT) thin films with different thicknesses as cover layers were deposited on the Ba_0.6Sr_0.4TiO₃ (BST) thin films on the Pt/Ti/SiO₂/Si substrates by radio frequency magnetron sputtering method. The microstructure, surface morphology, dielectric and tunable properties of BST/BZNT heterogeneous bilayered films were investigated as a function of the thickness of BZNT films and the effect of BZNT films on the asymmetric electrical properties of BST/BZNT bilayered films was discussed. It was found that BZNT cover layer significantly improved the leakage current and the dielectric loss, and the dielectric constant and tunability of BST/BZNT bilayered thin films simultaneously decreased with the increasing thickness of BZNT films. The BST/BZNT bilayered thin film with a 50 nm BZNT cover layer gave the largest figure of merit (FOM) of 33.48 with the upper tunability of 55.38%. The asymmetric electrical behavior of BST/BZNT bilayered films is probably related to an internal electric field caused by built-in voltages at Pt/BST and BZNT/Au interfaces.