热处理温度对Ba0.5Sr0.5TiO3薄膜结构与性能影响的研究

采用HPAgilent4294A阻抗分析仪、X衍射、扫描电镜等测试方法研究了热处理温度对BaxSr1-x，TiO3（BST）薄膜结构与性能的影响。当升／降温速率为0．5～1℃／min时，得到的薄膜表面均匀、无裂纹、孔洞。经过750℃退火处理后，薄膜的介电性能最佳，即具有较高的相对介电常数和较小的介质损耗。     

溅射功率对原位退火钴酸锂薄膜性能的影响

本文采用射频磁控溅射技术,在高温下制备了原位退火的钴酸锂薄膜,并研究了溅射功率对其性能的影响。结果表明,随着溅射功率的增加,钴酸锂薄膜结晶颗粒长大,生长速率增加,首次放电比容量增大且循环性能提升。200W溅射制备的钴酸锂薄膜首次放电比容量可达47μAh·cm~(-2)μm~(-1),并表现出较好的循环性能。     

退火温度对溅射法沉积Cu-Cr-O薄膜性能的影响

使用Cu Cr O2陶瓷靶材,利用射频磁控溅射方法在石英衬底上沉积了Cu-Cr-O薄膜,研究了退火温度对Cu-Cr-O薄膜结构及光电性能的影响。X射线衍射分析显示,退火温度为973 K时薄膜即已晶化并形成单相铜铁矿结构CuCrO2,随着退火温度的升高,薄膜结晶性逐渐提高。紫外-可见光谱与电学性能测量结果表明:薄膜可见光透过率随退火温度升高呈上升趋势,电导率则呈下降趋势,在973～1273K退火薄膜的可见光透过率最高为50%,电导率最高为0.12 S/cm。扫描电子显微镜照片显示,Cu-Cr-O薄膜电导率的下降主要与退火产生的微裂纹有关。     

底电极与组分对Ba1-xSrxTiO3薄膜结构与介电性能影响的研究

以Pt与La0.5Sr0.5CoO3为电极,采用溶胶-凝胶法分别沉积Sr/Ba比不同的Ba1-xSrxTiO3薄膜,研究结果表明:沉积在两种电极上的Ba1-xSrxTiO3薄膜,随着Sr/Ba比的增加,Ba1-xSrxTiO3薄膜的介电常数呈先增大后减小的趋势,当Sr含量为50%即为Ba0.5Sr0.5TiO3且频率为1 kHz时,薄膜具有最大的介电常数,分别是80,95和最小的介质损耗,分别是0.15,0.1.介电常数随着频率的升高呈下降趋势,介质损耗则成上升趋势.沉积La0.5Sr0.5CoO3电极上的Ba1-xSrxTiO3薄膜比Pt电极上的Ba1-xSrxTiO3薄膜具有更高的介电常数和低的介质损耗.     

铁电薄膜存储器底电极Pt/Ti的制备及性能研究

应用射频磁控溅射方法 ,在Si基片上采用不同的溅射工艺制备了铁电薄膜底电极Pt/Ti,并分析了在不同温度下退火后材料的电导率性能和粘结力性能 ,从理论和实验上分析了不同的溅射工艺和退火处理对底电极性能的影响。     

退火温度对铁电薄膜钛酸锶钡的影响

用醋酸盐和钛酸酯为原料,采用Sol-Gel工艺在Pt/TiO2/SiO2/Si基片上制备出Ba0.5Sr0.5TiO(3BST)铁电薄膜,然后在650-800℃下对BST薄膜进行退火,研究退火温度对钛酸锶钡铁电薄膜的影响。X射线衍射分析表明:退火温度在750℃以上时,BST薄膜转变成较为完整的ABO3型钙钛矿结构;SEM分析表明:750℃热处理的薄膜颗粒较大,且颗粒生长较好;阻抗分析仪测试表明:750℃退火处理的薄膜介电性能最佳;TEM分析表明:750℃晶粒发育完善、清晰,晶粒与晶粒之间比较紧密,且存在微畴区域。     

不同纤维增强对PZT/PVA复合材料性能影响的研究

压电陶瓷复合材料较低的力学性能限制其应用。为进一度探究纤维种类及掺量对锆钛酸铅(PZT)/聚乙烯醇(PVA)复合材料性能影响规律,对不同纤维掺量下碳纤维/PZT/PVA、芳纶纤维/PZT/PVA复合材料开展电学及力学性能测试,分析纤维种类、掺量及PZT/PVA体积比对试件介电、压电性能及弯曲、拉伸性能的影响规律,并结合电镜扫描(SEM)分析纤维掺量对试件性能的影响。结果表明,少量的纤维掺量能够提高复合材料的电学性能,过量的纤维使得复合材料结构孔隙结构增加,介质常数和压电常数均减小,介质损耗增大。7%芳纶纤维/0.5PZT/0.5PVA、5%芳纶纤维/0.6PZT/0.4PVA、3%芳纶纤维/0.7PZT/0.3PVA复合材料的介电性能和压电性能较高。芳纶纤维掺量为9%时,芳纶纤维/0.5PZT/0.5PVA、芳纶纤维/0.6PZT/0.4PVA、芳纶纤维/0.7PZT/0.3PVA、芳纶纤维/0.8PZT/0.2PVA复合材料的弯曲强度分别提高了10.72%、14.49%、13.85%及16.78%,拉伸强度分别提高了24.04%、23.94%、27.00%和28.52%。纤维在试件内...     

不同硅片对SBT薄膜结构与性能的影响

采用HPAgilent4294A阻抗分析仪、XRD、TEM等测试方法研究了不同电阻率硅片对Sr0.5Ba0.5TiO3(SBT)薄膜结构与性能的影响.在测试频率为1KHz时,在高阻硅片上生成的SBT薄膜的相对介电常数εr,介质损耗tanδ分别为100.54,0.060,材料的介电性能相对提高,并表现出较好的频散特性;最大εr温度点Tm(居里温度)稍微移向高温.在高阻硅片上制备的SBT薄膜易生成四方钙钛矿结构,薄膜表面无裂纹,孔洞少,比较致密,晶粒的平均粒径均为80nm,分布均匀;晶格条纹间距约为0.296nm,晶界2侧的晶粒取向是随机的.     

烧结温度对PCrNi-4压电陶瓷性能的影响

采用传统固相烧结法制备Pb0.94Sr0.06（Zr0.53Ti0.47）O3＋（Ni2O3＋Cr2O3）0.1wt%＋x wt%CeO2（简称PCrNi-4）压电陶瓷,其中x取值为0,0.1,0.3和0.5,研究了烧结温度对陶瓷样品的相结构、显微结构、压电及介电性能。结果标明：所有样品相结构均为三方相与四方向共存。当烧结温度为1280℃,CeO2掺杂量为0.3 wt%时,陶瓷的晶粒大小均匀,致密性良好,具有良好的压电及介电性能（d33=375 pC/N,Kp=0.70115,εT33=1400,tgδ=0.00238）。     

退火处理对玻璃表面沉积的ZnO薄膜微观形貌与性能的影响

以Zn(NO3)2·6H2O为前驱体,采用超声喷雾热解法在500℃下、在钠钙硅浮法玻璃衬底上制备了ZnO薄膜.分别在不同温度(500、550、600℃)和不同时间(30、60、120min)对制备的ZnO薄膜进行了退火处理.研究退火条件对ZnO薄膜微观结构、形貌以及光学性能的影响.结果表明:退火处理能提高ZnO薄膜的c轴取向;随着退火时间的延长,ZnO薄膜附着强度随之增加,但c轴取向度呈先增强,至120min时又开始呈下降的趋势;随着退火温度的升高,ZnO薄膜的c轴取向亦出现先显著增强,之后又开始下降的趋势,同时可见光透过率亦呈相同的变化趋势.最佳退火条件为500℃温度保温60min,此时薄膜不仅c轴取向生长优势明显,结晶质量良好,表面颗粒大小均匀,致密平滑,同时薄膜的可见光透过率由退火前的70％提高到90％.     

Effect of microstructure on the electrochemical behavior of Pt/YSZ electrodes

Two types of O₂,Pt/YSZ electrode preparation (Pt/YSZ cermet and sputtered platinum film) have been characterized by SEM and by cyclic voltammetry and chronoamperometry at 450 °C in 20 kPa oxygen. Cyclic voltammetry on the cermet and on the as-sputtered non-porous film electrode evidenced the characteristics of the PtO _x /Pt couple. The corresponding redox reaction occurs at the metal/electrolyte interface and it manifests itself by an anodic wave and one of more cathodic peaks in the voltammogram. Heat treatment of the sputtered electrode at 700 °C in oxygen atmosphere resulted in a porous structure by coalescence of the film. Cyclic voltammetry of the porous film electrode featured the characteristics of the O₂/O²⁻ couple, i.e. the redox reaction of gaseous oxygen occurring at the tpb. Chronoamperometry at anodic potentials showed similar features for both electrode preparations: an initial inhibition, a current peak and a slow activation, the latter being related to the phenomenon of electrochemical promotion of catalysis.     

Control of the Preferred Orientation in MFI Films Synthesized by Seeding

Single crystal silicon and quartz wafers were seeded with colloidal TPA-silicalite-1 crystals. Hydrothermal treatment of the seeded substrates was used to grow dense MFI films. The preferred orientation of the crystals constituting the films as a function of the amount and size of seeds, film thickness and hydrothermal treatment conditions was investigated. In thin films, most of the crystalline material was found to be oriented with the b-axes close to perpendicular to the substrate surface. In thick films, the a- or c-axes were close to perpendicular to the substrate surface depending on the conditions used for hydrothermal treatment. The seed size and amount was found to affect the rate of change in preferred orientation as a function of film thickness. A film growth mechanism which is able to explain the experimental results is proposed.     

微波法制备的压电复合材料结构和性能研究

利用微波原理合成出性能优良的压电复合材料,并研究了不同合成方法对复合压电材料的结构、介电和压电性能的影响。研究表明,微波合成与热压工艺获得的复合材料性能明显优于冷压工艺,两者的压电应力常数d33均在30pC/N左右。但微波工艺合成的复合材料的界面结合更好,有利于压电陶瓷的极化,其压电电压系数g33达42.8(V.m/N),更适合作为接收型传感器。     

Electrochemical decomposition of bisphenol A using Pt/Ti and SnO2/Ti anodes

Methodology for the electrochemical decomposition of bisphenol A is described. The electrochemical behaviour of bisphenol A at a Pt electrode was investigated by means of cyclic voltammetric techniques. The electrochemical oxidation of bisphenol A led to the deactivation of the electrode as a result of the deposition of an electropolymerized film. However the electrochemical decomposition of bisphenol A could be achieved by the use of a platinum coated titanium (Pt/Ti) electrode and a tin dioxide coated (SnO₂/Ti) electrode. The electrolysis was carried out galvanostatically at a constant current of 0.3 A. The mineralization of bisphenol A was monitored by determining the amount of total organic carbon. Furthermore, the generation and nature of intermediates produced in the electrochemical reactions was investigated. Although large amounts of aliphatic acids were generated by electrolysis with the Pt/Ti anode, they were produced only to a small extent in at the SnO₂/Ti anode. In the case of the SnO₂/Ti anode, bisphenol A is rapidly oxidized to carbon dioxide and water, compared to the Pt/Ti anode.     

溶胶-凝胶法制备掺钙钛酸锶铋铁电薄膜

利用溶胶-凝胶法在Pt/Ti/SiO2/Si衬底上制备了CaxSr1-xBi4Ti4O15(CxS1-xBT,x=0～1)铁电薄膜.研究了不同Ca2取代量对薄膜的微观结构、取向生长、铁电性能以及介电性能的影响.结果表明:当Ca2 取代量为x=0.4时,C0.4S0.6BT铁电薄膜样品在一定程度上沿a轴择优取向;样品致密性较好,晶粒呈球型,且大小均匀,尺寸约为100nm.C0.4S0.6BT薄膜的剩余极化强度为8.37μC/cm2,矫顽场强为72kWcm;在1 Hz～1 MHz频率范围内,相对介电常数为234～219,介电损耗为0.009～0.073.     

薄膜压电性能的测量方法

压电薄膜在微传感器和微致动器方面的应用日益受到重视.薄膜压电性能的测量方法与体材相比有很大不同.本文介绍了几种测量薄膜压电特性的方法,包括:激光干涉仪法,扫描探针显微镜法,垂直加载法等,并比较了这些方法的优缺点.对已有的测量结果进行了简要分析.     

PZT/PVDF体系压电复合材料的介电和压电性能研究

采用复合材料热压工艺,制备了0-3型PZT/PVDF(钛锆酸铅/聚偏二氟乙烯)压电复合材料。系统地研究了PZT体积分数对材料介电、压电性能的影响,并与Furukawa等人的理论预测进行了对比。结果显示在PZT体积分数为70％时,获得了性能优良的压电复合材料。在压电陶瓷高含量区,部分压电陶瓷颗粒相互联接,形成了类似0-3(1-3)型连通形式,获得了压电和介电性能优良的压电复合材料。     

Electrochemical degradation of Ibuprofen on Ti/Pt/PbO2 and Si/BDD electrodes

The electrochemical oxidation of Ibuprofen (Ibu) was performed using a Ti/Pt/PbO₂ electrode as the anode, prepared according to literature, and a boron doped diamond (BDD) electrode, commercially available at Adamant Technologies. Tests were performed with model solutions of Ibu, with concentrations ranging from 0.22 to 1.75 mM for the Ti/Pt/PbO₂ electrode and 1.75 mM for the BDD electrode, using 0.035 M Na₂SO₄ as the electrolyte, in a batch cell, at different current densities (10, 20 and 30 mA cm⁻²). Absorbance measurements, Chemical Oxygen Demand (COD) and Total Organic Carbon (TOC) tests were conducted for all samples. The results have shown a very good degradation of Ibu, with COD removals between 60 and 95% and TOC removals varying from 48 to 92%, in 6 h experiments, with higher values obtained with the BDD electrode. General Current Efficiency and Mineralization Current Efficiency, determined for both electrodes, show a similar behaviour for 20 mA cm⁻² but a very different one at 30 mA cm⁻². The combustion efficiency was also determined for both anodes, and found to be slightly higher with BDD at lower current density and equal to 100% for both anodes at 30 mA cm⁻².     

Electrochemical treatment of olive mill wastewater

Background Olive mill wastewater (OMW) constitutes a very strong agro‐industrial wastewater posing severe environmental threats in olive oil producing countries. The main objective of this study was to treat olive mill wastewater by electrochemical oxidation. The variables studied included the type and concentration of electrolyte solutions, voltage and time applied. Results: The electrolyte type and concentration significantly affected the degradation efficiency of the electrochemical oxidation. Optimal conditions for NaCl concentration were 3% (w/v) and 16 V. At these conditions chemical oxygen demand (COD) removal reached 70.8% after 8 h of electrochemical treatment, while color and turbidity were completely removed after short periods of treatment. However, bio‐assays indicated that the ecotoxicity of the treated wastewater remained unchanged, possibly due to the formation of chlorinated by‐products. Na₂SO₄ did not demonstrate sufficient efficiency. The simultaneous use of FeCl₃ and NaCl contributed to electro‐coagulation of OMW. After settlement, two separate phases were formed: the supernatant phase and the settled solids. Under optimal conditions (2% Na₂SO₄ + 1% FeCl₃; 24 V), the removal efficiency of COD reached 85.5% at the supernatant phase. Conclusion: NaCl was an effective electrolyte for OMW treatment. The electro‐coagulation process was also a successful process, but as in the case of NaCl the remaining acute toxicity of treated OMW was high. Copyright © 2007 Society of Chemical Industry