Characterization of lead zirconate titanate--lanthanum ruthenate thin film structures prepared by chemical solution deposition

In this work, the results of compositional and microstructural analysis of lead zirconate titanate--lanthanum ruthenate thin film structures prepared by chemical solution deposition are discussed. The cross-section transmission electron microscope (TEM) micrographs of the La-Ru-O film deposited on a SiO2/Si substrate and annealed at 700 degrees C revealed RuO2 crystals embedded in a glassy silicate matrix. When the La-Ru-O film was deposited on a Pt/TiO2/SiO2/Si substrate, RuO2 and La4Ru6O19 crystallized after annealing at 700 degrees C. After firing at 550 degrees C randomly oriented lead zirconate titanate (PZT) thin films crystallized on the La-Ru-O/SiO2/Si substrate, while on La-Ru-O/Pt/TiO2/SiO2/Si substrates PZT thin films with (111) preferred orientation were obtained. No diffusion of the Ru atoms in the PZT film was found. Ferroelectric response of PZT thin films on these substrates is shown in comparison with the PZT film deposited directly on the Pt/TiO2/SiO2/Si substrate without a La-Ru-O layer.     

Influence of substrate orientation on the morphologyand orientation of LaNiO3 thin films

LaNiO₃ thin films were successfully prepared by a chemical method from citrate precursors. The LNO precursor solution was spin‐coated onto Si (100) and Si (111) substrates. To obtain epitaxial or highly oriented films, the deposited layers were slowly heated in a gradient thermal field, with a heating rate of 1° min^?1, and annealed at 700°C. The influence of different substrate orientations on the thin film morphology was investigated using atomic force microscopy and X‐ray diffraction analysis. Well‐crystallized films with grains aligned along a certain direction were obtained on both substrates. Films deposited on both substrates were very smooth, but with a different grain size and shape depending on the crystal orientation. Films deposited on Si (100) grew in the (110) direction and had elongated grains, whereas those on Si (111) grew in the (211) direction and had a quasi‐square grain shape.     

硅基PZT压电功能结构研究

PZT压电薄（厚）膜是制备MEMS传感元件和执行元件重要的功能材料,对近年PZT薄（厚）膜在MEMS领域的研究现状进行了分析,提出了一种新型的双杯PZT/Si膜片式功能结构;采用有限元方法对双杯PZT/Si膜片进行了结构优化,得到PZT和上、下硅杯的结构优化值为DPZT: D1:D2 =0.75:1.1:1;一阶模态谐振频率为13.2KHz;以氧化、双面光刻、各向异性刻蚀,以及PZT厚膜丝网印刷等工艺技术制作了双杯硅基PZT压电厚膜膜片,该膜片具有压电驱动功能。双杯PZT/Si膜片式功能结构的MEMS技术兼容性好,对芯片内其它元件或电路的影响小,适合作为MEMS片内执行元件的驱动机构。     

Characterization of self-assembling isolated ferroelectric domains by scanning force microscopy

Lead zirconate titanate (PZT) thin films were prepared by a sol–gel process on platinized Si substrate. Their microstructure and surface morphology were characterized by XRD and Scanninn Force Microscopy. Phase transformation of the prepared PZT films from pyrochlore to ferroelectric was observed by XRD and PFM (piezoresponse force microscopy), respectively. Self-assembling nano-structured ferroelectric phases are fabricated by solution deposition technique followed by the controlling kinetics of the transformation. Complex structures of ferroelectric domains in the isolated ferroelectric phases were found in the furnace annealed PZT films in the temperature range of 400–500°C. Single ferroelectric domain structure in the isolated ferroelectric phases could be found in thinner PZT films and used to study the size effect of laterally confined ferroelectric domains.     

光纤持气率测井仪响应规律的实验研究

为考察现有光纤持气率计在油气水三相流中的响应特性,采用多相流标定装置对其进行测定,系统研究光纤持气率计在油量固定不变含水量不同条件下的持气率响应规律。实验结果表明,当油量为5m3/d、气量小于10m3/d时,持气率随含气量的增大而增大,二者线性变化程度较低;而气量在10～35m3/d之间变化时,持气率随含气量的增大而线性增大。     

基于激光多普勒技术的PZT薄膜压电性能测试研究

应用基于激光多普勒技术的微小形变分析方法,并引入数字锁相技术,成功实现了PZT(Pb(Zr,Ti)O₃)铁电薄膜的压电性能测试。对商用压电陶瓷在小信号激励下的压电性能测试表明,数字锁相技术的引入能有效抑制系统噪声,并提高激光多普勒系统的位移检测分辨率,使其达到皮米量级。此外,研究了用溶胶-凝胶技术和溶胶-电雾化技术制备得到的PZT薄膜的电压-位移曲线和压电位移"蝴蝶线",实验结果表明:在5 V直流偏置下测得两种方法制备得到的PZT薄膜的d₃₃压电系数分别为218.7 pC/N和215.8 pC/N,相应的标准偏差分别为12.7和28.6。     

Characteristics of Sputter-deposited Gadolinia-doped Ceria Thin Films on Al2O3/SiO2/Si Systems

Metal oxide films prepared by thin film technology have been reported for the potential applications on thin solid electrolyte layers for solid oxide fuel cells(SOFCs). Gadolinia-doped ceria(GDC) thin films and Al2O3 layers on SiO2/Si substrates are successively deposited by RF reactive magnetron sputtering from a cerium-gadolinium (90:10 at.%) alloy target and Al target in O2/Ar gas mixture and then perform post-thermal treatments at 300-700 ℃ and 900 ℃ for 2 h, respectively. Materials characteristics and chemical compositions of GDC films and Al2O3 layers are investigated by X-ray photoelectron spectroscopy(XPS), cross-sectional scanning electron microscopy(SEM), X-ray diffraction(XRD), and atomic force microscopy(AFM). Stoichiometric Al2O3 layers with polycrystalline structures are firstly prepared onto SiO2/Si substrates. A cubic fluorite structure with columnar crystallites of GDC films is successfully deposited on Al2O3/SiO2/Si systems. The chemical composition of 700 ℃-annealed GDC films is (Ce0.91Gd0.09)O1.94 and possesses a higher film density of 7.257 g/cm3. As a result, GDC thin films prepared by RF reactive magnetron sputtering and post-thermal treatments can be used as thin solid electrolyte layers for intermediate temperature SOFCs system as compared to the well-known yttria-stabilized zirconia(YSZ).     

厚度效应对Pb(Zr0.53Ti0.47)O3薄膜微结构、铁电、介电性能的影响

用改进的溶胶-凝胶法在Pt(111)/Ti/SiO₂/Si(100)衬底上制备了不同厚度的高度(111)取向的Pb(Zr_0.53Ti_0.47)O₃薄膜.运用X射线衍射(XRD)和原子力显微镜(AFM)分析了薄膜的微结构,原子力显微镜表明厚度为0.3μm和0.56μm的PZT薄膜的晶粒尺寸和表面粗糙度分别为0.2～0.3μm、2～3μm和0.92nm、34nm.0.3μm和0.56μm PZT薄膜的剩余极化(Pr)和矫顽场(Ec)分别为32.2μC/²、79.9kV/cm, 27.7μC/cm²、54.4kV/cm;在频率100KHz时,薄膜的介电常数和介电损耗分别为539、0.066,821、0.029.     

聚酰亚胺自支撑膜的制备及其表面形貌

采用物理气相沉积法,在加热或不加热的抛光玻璃基片上蒸镀N aC l脱膜剂,再混合蒸镀均苯四甲酸二酐(PMDA)和二氨基二苯醚(ODA)两种单体,然后在空气环境中对样品进行热亚胺化。在去离子水中脱膜后获得厚度为100nm的聚酰亚胺自支撑膜。采用傅里叶变换红外光谱仪(FT IR)对样品进行化学结构分析并且根据谱线计算了不同热处理下薄膜的亚胺化程度。采用原子力显微镜,对样品进行表面形貌分析,结果表明给基片加热能改善聚酰亚胺薄膜的表面形貌。     

RLVIP制备Ge1－xCx薄膜的X射线光电子能谱研究

应用低压反应离子镀（Reactive Low Voltage Ion Plating：RLVIP）在Ge基底上沉积了Ge1-xCx薄膜。制备过程中,低压等离子源作为辅助等离子源,Ge作为蒸发材料,CH4作为反应气体,在相同的条件下以不同沉积速率制备了C含量( x )从0.23到0.78的Ge1-xCx薄膜。X射线衍射测试表明制备的Ge1-xCx薄膜为无定形结构。通过X射线光电子能谱研究了不同C含量下Ge1-xCx薄膜的化学键合变化。测试结果表明当 x > 0.78时,成键为C-H键;当x在0.53至0.62时,成键为C-C键;当x < 0.47时,成键为Ge-C键。     

Influence of target grit count and sintering temperature on pulsed laser deposition of SiC thin films

A pulsed laser deposition (PLD) technique for depositing SiC on Si(100) substrates using Nd³⁺:YAG laser at 355 nm is studied. The influence of substrate temperature, ambient pressure, and SiC powder grit size on both structure and morphology of SiC thin film is investigated. Further, the influence of the target preparation on the reduction of droplet formation during Nd³⁺:YAG laser-assisted pulsed laser deposition of SiC thin films is investigated. Experimental studies show that multicrystalline SiC film can be obtained with temperature ranging from 600 to 700 °C and at an ambient pressure of about 5.5 × 10^?3 Pa. Further, droplet formation on the deposited film was reduced significantly by selecting the grit count of SiC powder 500 and the pressure of 2 × 10^?2 Pa. SiC target sintered at 1,600 °C showed a reduced wear during the laser ablation. The X-ray diffraction (XRD) and the Raman spectroscopy studies on deposited films clearly show the multicrystalline (combined 3C-SiC and 4H-SiC) nature of SiC films. I-V characteristics of deposited SiC film on n-type c-Si substrate also indicated that SiC thin film possesses P-type semiconductor properties.     

Fabrication of ionic liquid thin film by nano-inkjet printing method using atomic force microscope cantilever tip

We demonstrate the fabrication of thin films of ionic liquid (IL), 1-butyl-3-methyl-imidazolium tetrafluoborate, by nano-inkjet printing method using an atomic force microscope (AFM) cantilever. The IL filled in a pyramidal hollow of the AFM cantilever tip was extracted from an aperture at the bottom of the hollow and deposited onto a Pt substrate when the bias voltage was applied between the cantilever and the substrate. We succeeded in fabricating IL thin films with a thickness of 4 nm. The areas and thicknesses of IL thin films were controlled by the fabrication conditions in this method, which is also useful for the investigations of nanometer-scale properties of ionic liquid.     

退火对真空蒸发Ti3O5制备光学薄膜性能的影响

采用真空蒸发法,以T i3O5为膜料分别在基片温度为200℃、250℃、300℃的条件下制备氧化钛光学薄膜,XRD结果显示,沉积态薄膜为无定形态,400℃退火后,均由无定形态向锐钛矿结构转变;不同基片温度下制备的氧化钛薄膜退火后,折射率均随基片温度的升高而增大;随着退火温度的升高,(101)晶相择优取向十分明显,结晶度增大;经过400℃、500℃、600℃退火后,薄膜折射率逐渐上升。     

Design and implementation of a versatile and variable-frequency piezoelectric coefficient measurement system

We present a simple but versatile piezoelectric coefficient measurement system, which can measure the longitudinal and transverse piezoelectric coefficients in the pressing and bending modes, respectively, at different applied forces and a wide range of frequencies. The functionality of this measurement system has been demonstrated on three samples, including a PbZr(0.52)Ti(0.48)O(3) (PZT) piezoelectric ceramic bulk, a ZnO thin film, and a laminated piezoelectric film sensor. The static longitudinal piezoelectric coefficients of the PZT bulk and the ZnO film are estimated to be around 210 and 8.1 pC∕N, respectively. The static transverse piezoelectric coefficients of the ZnO film and the piezoelectric film sensor are determined to be, respectively, -0.284 and -0.031 C∕m(2).     

内箝位型压电精密步进旋转驱动器

提出一种新型的压电精密步进旋转驱动器。该驱动器以仿生运动的原理,以压电陶瓷叠堆为动力源,采用定子内侧箝位的方式和薄壁柔性铰链微变形结构,提高该驱动器箝位的稳定性和步进旋转的稳定性。通过静力学有限元分析和动力学分析,较深入地研究了该驱动器的运动特性,并对驱动器旋转分辨率、旋转速度、驱动转矩等方面进行试验研究。研制的内箝位型压电精密步进旋转驱动器能够实现高频率(40 Hz),较高速度(325 μrad /s),大行程(大于360°),高分辨率(1 μrad),较大驱动力矩(30 N·cm)等特点,有效提高了压电精密步进旋转驱动器的驱动性能。该驱动器在精密运动、微操作、光学工程以及精密定位等精密工程中具有广阔的应用前景。     

Hardness properties and high-temperature wear behavior of nitrided AISI D2 tool steel, prior and after PAPVD coating

Wear experiments in the range of 25–600 °C have been conducted on samples of D2 tool steel in different conditions involving unnitrided, nitrided and nitrided and coated with Balinit^® A (TiN) and Balinit^® Futura (TiAlN) deposited industrially at Balzers (Amherst, NY, USA), by means of PAPVD. The results indicate that coating the nitrided D2 tool steel substrate with these two films gives rise to an improvement of 97% (TiN) and 99% (TiAlN) in the wear behavior at the test temperature of 300 °C, in comparison with the uncoated substrate. However, at a temperature of 600 °C, besides oxidation of the coatings, the mechanical strength of the substrate decreases giving rise to fracture and delamination of the films. At this temperature the uncoated substrate exhibited the highest resistance to sliding wear, presumably due to the formation of a well bonded surface glazed layer which gives rise to a significant reduction in the friction coefficient. The indentation experiments that were conducted with the nitrided steel substrate and the coated systems indicates that the nitriding process applied to the D2 steel prior to PAPVD coating provides a satisfactory load support which contributes to the improvement of the coated systems capability to withstand indentation loads at room temperature. In this regard, the coated system with a TiAlN coating displayed a better behavior than that shown by the system with a TiN coating. An experimental procedure is proposed in order to predict the hardness profile of the nitrided tool steel, along the cross section of the material, just from hardness measurements taken on the surface of the sample, employing different indentation loads.     

Patterned crack-free PZT thick films for micro-electromechanical system applications

The fabrication and structuring of multilayer-thick film piezoelectric (PZT-lead zirconate titanate) structures, using composite sol-gel techniques and wet etching is described. The composite sol-gel technique involves producing a PZT powder/sol composite slurry which when spun down, yields films a few micrometres thick. Repeated layering and infiltration has been used to produce PZT films between 10 and 40 μm thick. Due to the low firing temperature (<720°C), it has also been possible to produce PZT films with embedded thin (ca. 100 nm thick) metal electrodes. The PZT thick films have also been structured using a wet etching technique. Examples of features and cavities with lateral dimensions in the order of tens of micrometres are presented. The ability to fabricate and structure thick functional films with embedded metal electrode structures offers the possibility to create novel micro-device structures suitable for use in micro-electromechanical systems (MEMS).     

Surface modification of diamond-like carbon coatings to control over run-in processes in friction pair

The effect of the nanostructure and chemical composition of thin Mo–Se–C films on the run-in of the diamond-like carbon coating (a-C) and the steel counterbody during ball-on-disk sliding test is studied. At the final stage of the deposition of the a-C coating on the steel substrate, a flow of atoms from the MoSe₂ target was added to the flow of atoms being deposited. The influence of the air humidity on the selection of optimum structure and chemical composition of the film, which provide a fairly low (<0.07) coefficient of friction during the entire period of the run-in stage, is considered. In order to explain the effect of the modifying films, analysis of the specific features of the friction-induced changes in the composition of the films during wear debris formation has been carried out using Raman spectroscopy.     

压电直线精密驱动器研究

提出一种新型的压电直线精密步进驱动器。该驱动器采用仿生运动的原理,以定子主动箝位的方式和双侧薄壁铰链微变形结构,解决了以往压电精密驱动器箝位不牢固、步进频率较低、行程小、分辨率低、速度低、驱动力不稳定等问题。研制的精密直线驱动器能够实现高频率100 Hz,高速度30 mm/min,大行程>10 mm,高分辨率0.05 μm,大驱动力100 N等特点,大幅度提高了压电型步进驱动器的驱动性能。     

磁过滤阴极弧法TiN薄膜的制备及其微观机械性能研究

采用“S”型磁过滤阴极弧等离子体沉积技术,室温下在（111）面单晶硅上沉积氮化钛薄膜。采用AFM和XRD技术分别对薄膜的表面形貌和晶体择优取向进行了表征,并用微刻划的方法分析薄膜的微观机械性能。结果表明,薄膜表面光滑致密,随偏压的增大,表面颗粒粒径先增大后减小,并且从（111）面的择优取向转变成（220）面。在刻划实验中,随载荷增加,薄膜先后经历了完全弹性变形,弹-塑性变形和脆性断裂阶段。利用直接和间接2种方法对得到的薄膜的临界载荷进行分析对比,发现在不同负偏压下,薄膜的内应力和临界载荷不同。随着负偏压的增大,薄膜的内应力逐渐增大,临界载荷逐渐减小。在-100V偏压下制备的氮化钛薄膜的微观机械性能最为理想。