Pb(Zr0.3Ti0.7)O3铁电薄膜激光感生电压效应

采用脉冲激光沉积(PLD)技术在LaSrAlTaO₃(LSATO),LaAlO₃(LAO)和SrTiO₃(STO)的单晶倾斜衬底上成功制备了Pb(Zr_0.3Ti_0.7)O₃(PZT)薄膜,在三种倾斜衬底上生长的PZT薄膜中都首次发现了LIV效应.对PZT/LSATO薄膜在a,c轴两种不同取向择优生长下的LIV效应做了研究,发现在薄膜c轴取向择优生长 关键词： 激光感生电压效应 铁电薄膜 薄膜生长取向 原子层热电堆     

低电场下LiNbO3薄膜在非晶衬底上的取向生长

报道了外加低电场和衬底温度对脉冲激光淀积法制备的LiNbO₃薄膜取向的影响.在衬底温度为600℃和外加电场为7V/cm的条件下，在石英玻璃等非晶态衬底上获得了完全(001)取向的LiNbO₃薄膜.在对具有自发极化的LiNbO₃在电场作用下成核生长机制和温度对LiNbO₃自发极化强度的影响进行分析的基础上，给出了低电场诱导铁电薄膜取向生长的物理依据. 关键词：     

化学溶液法制备的Pb(Mg1/3Nb2/3)O3-PbTiO3薄膜的光学性能

用化学溶液方法在宝石衬底及有LaNiO₃缓冲层的Pt/TiO₂/SiO₂/Si衬底上制备了92%Pb(Mg_1/3Nb_2/3)O₃-8%PbTiO₃(PMNT)薄膜，X射线衍射测试结果表明：在有LaNiO₃缓冲层的Pt/TiO₂/SiO₂/Si衬底上制备的PMNT薄膜几乎是纯钙钛矿相，且薄膜 关键词： PMNT薄膜 光学性能 化学溶液法     

SrRuO3超薄膜制备条件和拓扑霍尔效应的关联

使用激光分子束外延在SrTiO₃(001)衬底上生长SrRuO₃薄膜,并研究激光能量密度、生长温度和靶材表面烧蚀度等生长参数对于SrRuO₃表面形貌、基本磁电性质以及拓扑霍尔效应的影响.当在最优条件下生长SrRuO₃薄膜时,样品表面平整、台阶清晰,具有最低的金属-绝缘体转变温度,电阻率最低,且具有最显著的拓扑霍尔效应;而改变生长参数生长的SrRuO₃薄膜由于存在更多的缺陷,其表面较粗糙,金属-绝缘体转变温度增大,或表现出绝缘体行为,而拓扑霍尔效应会变弱甚至消失.     

La0.3Sr0.7TiO3模板层对Pb(Zr0.5Ti0.5)O3薄膜的铁电性能增强效应的研究

通过sol-gel法在Si (111) 基片上分别制备了LaNiO₃(LNO)底电极和LaNiO₃/La_0.3Sr_0.7TiO₃ (LNO/LSTO)底电极.然后采用sol-gel 方法，在两种衬底上分别制备了Pb (Zr_0.5Ti_0.5)O₃ (PZT)铁电薄膜.XRD分析表明，两种PZT薄膜均具有钙钛矿结构，且在LNO底电极上的PZT薄膜呈(100) 择优取向，而在LNO/LSTO底电极上的PZT薄膜呈随机取向.铁电性能测试表明，相对LNO衬底上制备的PZT薄膜，在LNO/LSTO底电极上制备的PZT薄膜的剩余极化强度得到了有效的增强，同时矫顽场也增大.介电常数和漏电流的测试表明，LNO/LSTO底电极上制备的PZT薄膜具有大的介电常数和漏电流. 关键词： PZT薄膜 铁电性 漏电流 0.3Sr_0.7TiO₃')" href="#">La_0.3Sr_0.7TiO₃     

GaSb基PECVD法制备SiO2薄膜的应力研究

为了实现在GaSb衬底上获得低应力的SiO₂薄膜,研究了等离子体增强化学气相沉积法（PECVD）在晶格失配较大的GaSb衬底上沉积SiO₂薄膜的应力情况。通过改变薄膜沉积时的工艺条件,如反应温度、射频功率、反应压强、气体流量比,并基于曲率法模型,对镀膜前后的曲率半径进行了实验测量,利用Stoney公式计算相关应力值并绘制应力变化曲线。详细讨论了PECVD工艺条件的改变对SiO₂薄膜应力所产生的影响。同时通过在Si衬底上沉积SiO₂薄膜,对比分析了导致薄膜应力产生的因素及变化过程。实验结果表明,在沉积温度为300℃、射频功率为20 W、腔体压强为90 Pa、气体流量比SiH₄/N₂O为125/70 cm³·min^-1的工艺参数下,PECVD法在GaSb衬底上沉积的SiO₂薄膜应力相对较小。     

蓝宝石衬底上Gd2O3掺杂CeO2氧离子导体电解质薄膜的生长及电学性能

采用反应磁控溅射方法,在(0001)蓝宝石单晶衬底上,制备了纳米多晶Gd₂O₃掺杂CeO₂(GDC)氧离子导体电解质薄膜,采用X射线衍射仪(XRD)、原子力显微镜(AFM)对薄膜物相、结构、粗糙度、表面形貌等生长特性进行了表征,利用交流阻抗谱仪测试了GDC薄膜不同温度下的电学性能;实验结果表明,GDC薄膜为面心立方结构,在所研究的衬底温度范围内,均呈强(111)织构生长;薄膜表面形貌随衬底温度发生阶段性变化：衬底温度由室温升高到300℃时, 关键词： 2O₃掺杂CeO₂电解质薄膜')" href="#">Gd₂O₃掺杂CeO₂电解质薄膜 反应磁控溅射 生长特性 电学性能     

La0.5Sr0.5CoO3薄膜的外延生长及其机理研究

利用脉冲激光制膜法,在多种衬底和温度条件下,系统研究了La_0.5Sr_0.5CoO₃(LSCO)薄膜的结构和外延生长特性,在LaAlO₃,SrTiO₃和MgO衬底上实现了LSCO薄膜的外延生长.外延生长的薄膜具有低的电阻率和金属性导电特征.研究表明,外延生长的最佳温度范围为700—800℃,最佳衬底为LaAlO₃.并着重探讨了衬底材料和淀积温度等多种因素对LSCO薄膜的生长与性 关键词：     

氧压对SrTiO3和SrNb0.2Ti0.8O3薄膜晶格参数的影响及激光感生热电电压效应

采用脉冲激光沉积技术制备了SrTiO₃和SrNb_0.2Ti_0.8O₃薄膜.X射线衍射分析表明在LaAlO₃(100)单晶平衬底上生长的SrTiO₃及SrNb_0.2Ti_0.8O₃薄膜是沿［001］取向的近外延生长.随着氧压在一定范围内逐渐增大,SrTiO₃薄膜的晶格参数减小,而SrNb_0.2Ti_0.8O₃薄膜的晶格参数先减小后增大.同时摸索出制备具有二维电子气超晶格(SrTiO₃/SrNb_0.2Ti_0.8O₃)_L的最佳氧压为1.0×10^-2Pa.另外在LaAlO₃(100)倾斜衬底上制备的SrNb_0.2Ti_0.8O₃薄膜中观察到激光感生热电电压效应. 关键词： 0.2Ti_0.8O₃薄膜')" href="#">SrNb_0.2Ti_0.8O₃薄膜 晶格参数 激光感生热电电压 脉冲激光沉积     

激光分子束外延BaTiO3薄膜最顶层表面原子平面与薄膜生长机理

用激光分子束外延技术在SrTiO₃(001)衬底上外延生长了高质量的BaTiO_{3< /sub>薄膜,薄膜的生长过程由反射式高能电子衍射仪(RHEED)原位实时监测,表明薄膜具有 二维层状生长模式.薄膜的晶体结构和表面形貌分别由X射线衍射和原子力显微镜表征,显示 该薄膜为完全c轴取向四方相晶体结构,其表面具有原子尺度光滑性.采用角分辨X射线光电 子谱技术(ARXPS),研究了BaTiO3薄膜表面最顶层原子种类和排列状况.结果表 明,BaTiO3 关键词： 激光分子束外延 3薄膜')" href="#">氧化物BaTiO3薄膜 最顶层表面 角分辨X射线光电子谱}     

Microstructure and electrical properties of Ba0.5Sr0.5TiO3 thin films prepared on copper foils with La2O3 buffer layers

Ba_0.5Sr_0.5TiO₃ (BST) thin films were deposited on copper foils via sol-gel method with La₂O₃ as a buffer layer. The films were processed in almost inert atmosphere so that the substrate oxidation was avoided while allowing the perovskite film phase to crystallize. The existence of a La₂O₃ buffer layer between the BST thin film and Cu foil improved the dielectric constant and reduced the leakage current density of the BST thin film. Meanwhile, the BST thin film exhibited ferroelectric character at room temperature, which was contrast to the para-electric behavior of the film without the buffer layer. Effects of La₂O₃ buffer layer on the crystallizability and microstructure of BST thin films were also investigated.     

The role of a ZnO buffer layer in the growth of ZnO thin film on Al2O3 substrate

A ZnO buffer layer and ZnO thin film have been deposited by the pulsed laser deposition technique at the temperatures of 200 C and 400 C, respectively. Structural, electrical and optical properties of ZnO thin films grown on sapphire (Al₂O₃) substrate with 1, 5, and 9 nm thick ZnO buffer layers were investigated. A minute shift of the (101) peak was observed which indicates that the lattice parameter was changed by varying the thickness of the buffer layer. High resolution transmission electron microscopy (TEM) was used to investigate the thickness of the ZnO buffer layer and the interface involving a thin ZnO buffer between the film and substrate. Selected area electron diffraction (SAED) patterns show high quality hexagonal ZnO thin film with 30 in-plane rotation with respect to the sapphire substrate. The use of the buffer can reduce the lattice mismatch between the ZnO thin film and sapphire substrate; therefore, the lattice constant of ZnO thin film grown on sapphire substrate became similar to that of bulk ZnO with increasing thickness of the buffer layer.     

GROWTH MODE OF Cu-RICH PARTICLES ON LASER-ABLATED YBa2Cu3O7 THIN FILMS

The microstructure of the laser-ablated YBa₂Cu₃O₇ (YBCO) thin film deposited on heated (100) SrTiO₃ substrate was examined by transmission electron microscope. The par-ticles on the film mainly consist of CuO and few CuYO₂. Most of these non-superconducting particles nucleate on or near the surface of the film and protrude about 100-400 nm in height, A large amount of a-axis YBCO grains also exist in the film, which nucleate at the substrate surface and grow perpendicularly above the c-axis YBCO film. The YBCO thin film deposited under low oxygen pressure has very different microstructure compared with YBCO thin film deposited under high oxygen pressure.     

Epitaxial strain-induced magnetic anisotropy in Sm3Fe5O12 thin films grown by pulsed laser deposition

Sm₃Fe₅O₁₂ thin films of various thicknesses were grown on a (0 0 1)-oriented Gd₃Ga₅O₁₂ substrate by pulsed laser deposition. The crystal structure of the films was strongly dependent on film thickness. The lattice was strained for thinner films due to a lattice mismatch between the film and substrate. This lattice strain was relaxed when the film thickness exceeded a critical thickness of around 660 Å. It is suggested that the epitaxial strain induces uniaxial magnetic anisotropy with an out-of-plane magnetic easy axis.     

La0.8Ca0.2MnO3/SrTiO3薄膜厚度对其结构及磁学性能的影响

采用多种X射线衍射技术和磁电阻测量技术研究了不同厚度的La_0.8Ca_0.2MnO₃/SrTiO₃ (LCMO/STO)薄膜的应变状态及其对磁电阻性能的影响.结果表明，在STO(001)单晶衬底上生长的LCMO薄膜沿［00l］取向生长.LCMO薄膜具有伪立方钙钛矿结构，随着薄膜厚度的增加，面内晶格参数增加，垂直于面内的晶格参数减小,晶格参数a和b相近，略小于c.LC 关键词： X射线衍射 微结构 应变 物理性能     

Electron beam-physical vapor deposition of SiC/SiO2 high emissivity thin film

When heated by high-energy electron beam (EB), SiC can decompose into C and Si vapor. Subsequently, Si vapor reacts with metal oxide thin film on substrate surface and formats dense SiO₂ thin film at high substrate temperature. By means of the two reactions, SiC/SiO₂ composite thin film was prepared on the pre-oxidized 316 stainless steel (SS) substrate by electron beam-physical vapor deposition (EB-PVD) only using β-SiC target at 1000 °C. The thin film was examined by energy dispersive spectroscopy (EDS), grazing incidence X-ray asymmetry diffraction (GIAXD), scanning electron microscopy (SEM), atomic force microscopy (AFM), backscattered electron image (BSE), electron probe microanalysis (EPMA), X-ray photoelectron spectroscopy (XPS) and Fourier transformed infra-red (FT-IR) spectroscopy. The analysis results show that the thin film is mainly composed of imperfect nano-crystalline phases of 3C-SiC and SiO₂, especially, SiO₂ phase is nearly amorphous. Moreover, the smooth and dense thin film surface consists of nano-sized particles, and the interface between SiC/SiO₂ composite thin film and SS substrate is perfect. At last, the emissivity of SS substrate is improved by the SiC/SiO₂ composite thin film.     

Growth and characterization of Y2O3 thin films

Y₂O₃ thin films were grown on silicon (1 0 0) substrates by pulsed-laser deposition at different substrate temperatures and O₂ pressures. The structure and composition of films are studied by using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The Y₂O₃ thin films deposited in vacuum strongly oriented their [1 1 1] axis of the cubic structure and the film quality depended on the substrate temperature. The magnitude of O₂ pressure obviously influences the film structure and quality. Due to the silicon diffusion and interface reaction during the deposition, yttrium silicate and SiO₂ were formed. The strong relationship between composition and growth condition was discussed.     

2-2型磁电复合薄膜CoFe2O4/Pb(Zr0.53Ti0.47)O3静磁耦合

运用溶胶-凝胶法在Pt/Ti/SiO₂/Si基片上旋涂制备了2-2型CoFe₂O₄/Pb(Zr_0.53Ti_0.47)O₃磁电复合薄膜．制备的磁电薄膜结构为基片/PZT/CFO/PZT*/CFO/PZT,通过改变中间层PZT*溶胶的浓度,改变磁性层间距以及静磁耦合的大小．SEM结果表明,复合薄膜结构致密,呈现出界面清晰平整的多层结构．制备的复合薄膜具有较好的铁电与铁磁性能．实验还研究了静磁耦合对薄膜磁电性能的影响,结果表明,随着复合薄膜磁性层间距的减小,静磁耦合效应的增加,磁电电压系数有逐渐增大的趋势.     

Preparation and conducting performance of LaNiO3/Ag film and its interface reaction

LaNiO₃ thin film with perovskite structure was successfully prepared on Ag substrate via an amorphous heteronuclear complex LaNi(DTPA)·6H₂O as a precursor. The influences of precursor concentration and PEG additive with different molecular weight on the texture of the film were carefully studied. The interface states of LaNiO₃/Ag film were revealed by using AES analysis. The effect of annealing time on the interface diffusion of the LaNiO₃/Ag film was shown by using AES depth profile spectrum. The relationship between the electric resistivity of the film and the environmental temperature was measured by using four-probe method. The results showed the film had good metallic conductivity from 300 down to 77 K.     

Film thickness dependence of electro-optic effect in epitaxial BaTiO3 thin films

Based on the phenomenological Landau-Devonshire theory, we investigate the film thickness dependence of ferroelectric and electro-optic properties of epitaxial BaTiO₃ thin films grown on SrTiO₃ and MgO substrates. By using the effective substrate lattice parameter concept, the film thickness dependence of misfit strain is incorporated into the theory. Therefore, the film thickness dependence of ferroelectric and electro-optic properties in epitaxial BaTiO₃ thin films can be explained. Moreover, a large quadratic electro-optic effect was obtained in the BaTiO₃ thin films, which is in good agreement with the experimental result of BaTiO₃ thin films on the MgO substrate.