La掺杂浓度对PLZT薄膜红外光学性质的影响

采用溶胶-凝胶法在Pt/Ti/SiO2/Si衬底上制备了不同La掺杂浓度PLZT(x/40/60)薄膜- x射线衍射分析表明制备的PLZT(x/40/60)薄膜是具有单一钙钛矿结构的多晶薄膜- 通过红外椭圆偏振光谱仪测量了波长为2-5—12-6μm范围内PLZT薄膜的椭偏光谱，采用经典色 散模型拟合获得PLZT薄膜的红外光学常数，同时也拟合获得PLZT薄膜的厚度- 随着La掺杂浓 度的增大，折射率逐渐减小- 而消光系数除PLZT(4/40/60)薄膜外，呈现逐渐增大的趋势- 分析表明这些差异主要与PLZ 关键词： PLZT薄膜 红外光学性质 红外椭圆偏振光谱     

掺铥PLZT透明光电陶瓷的光辐射特性

根据J-O理论研究掺Tm3+的光电陶瓷PLZT的激光潜能，利用Tm3+的420?2000 nm的吸收光谱拟合出了其强度参量，即?2=9.133￡10-21 cm2, ?4=1.529￡10-21 cm2和?6=1.712￡10-21 cm2，进而由强度参量计算了辐射跃迁几率、辐射寿命、荧光分支比和1865 nm荧光峰的受激发射截面等光学参数．     

掺La锆钛酸铅压电陶瓷(PLZT)在光Kerr效应教学实验中的应用

通过实验表明高掺La的PLZT具有较高的二次电光系数,用PLZT做Kerr效应教学实验具有明显的优势。     

Domain reorientation dynamics of sol–gel derived strontium doped PLZT (8/65/35)

Polycrystalline samples of PLSZT with the composition Pb_0.92−x La_0.08Sr _x (Zr_0.65Ti_0.35)O₃ (where x = 0, 0.02, 0.04, 0.06, 0.08, and 0.10) have been synthesized by sol–gel technique. DTA analysis confirms that all the organic constituents get decomposed and final PLZT is formed at 545 °C. The XRD analysis suggests the formation of single rhombohedral perovskite phase with decreasing unit cell parameter. Crystallite size calculated, using Scherrer’s equation, was found to decrease with Sr doping due to smaller ionic radii of Sr than Pb. Compact uniform grain distribution was observed from SEM micrographs. The ferroelectric to paraelectric phase transition temperature, maximum dielectric constant and remanent polarization (P _r) were found to decrease with Sr doping along with increasing diffuse nature of phase transformation. Detailed domain reorientation dynamics study suggests that Sr doping increases the percentage backswitching and decreases the normalized coercivity by decreasing the viscous nature of composition.     

过氧化合物法PLZT纳米粉体的制备和表征

掺镧的锆钛酸铅固溶体（Pb1-x,Lax）(Zry,Ti-y)1-x/4O3（简称PLZT）是一种有重要用途、性能优良的电光陶瓷材料[1]。为避免局部组成变化引起散射和保证良好的电光性能,材料的组成和均匀性非常重要。用传统的固相法制备PLZT粉体耗能大,生成的粉体颗粒大,组成均匀性差,不能满足现代高科技应用的要求。近年来研究的溶胶．凝胶[2]、柠檬酸法[3]、EDTA凝胶法[4]等湿化学法有许多优点,受到人们的关注,但这些方法需用较贵原料。而在众多的湿化学法中,以共沉淀法最为经济,并且它比传统的固相法好,能够制得均匀性好的纳米粉体。但该…     

水热条件下形成的PLZT固溶体的X射线分析

用Ｘ射线分析研究了不同水热条件下（１３０～２２０℃，ＣＫＯＨ＝１～５ｍｏｌ／Ｌ，Ｚｒ／Ｔｉ＝０／１０～１０／０，Ｐｂ／（Ｚｒ＋Ｔｉ）＝１．０～１．７，ｘ（Ｌａ）＝０～２０％）四元系ＰＬＺＴ固溶体的形成，Ｌａ（３＋）在上述水热条件下不易进入固溶体晶格取代Ａ位的Ｐｂ（２＋）或Ｂ位的Ｚｒ（４＋）和Ｔｉ（４＋），而可能存在于晶界处或被吸附在颗粒的表面上，通过热处理逐渐进入晶格。在固溶体的四方相区易发生Ａ位取代，使晶胞收缩，轴比减小．在三方相区可能同时发生Ａ位与Ｂ位取代，晶胞体积稍有缩小．Ｌａ（３＋）的存在有利于三方－四方同质异构相界区固溶体的形成。反应温度和矿化剂ＫＯＨ的浓度对产物固溶体的形成及其形貌有重要影响。     

Powderless processing of ceramics: Thin-layer electroceramics

A review is made of progress on the sol-gel processing of dense insulating electroceramics by polymeric condensation routes. Up until the past ten years, powders and porous coatings were principally made for optical and conductive applications. Much effort was expended on silica (SiO₂) and silicate-based systems. Recently, these approaches have been extended to non-silicate systems [1]. In this paper information is presented for the powderless processing of selected electroceramics in thin-layer form. Materials include PbTiO₃, BaTiO₃, Ba_1–x Pb _x TiO₃, PbZrO₃, Pb(Zr_1–y Ti _y )O₃ and (Pb_1–x La _x )(Zr_1–y Ti _y )O₃ which find applications in ceramic capacitors, piezoelectric transducers and electrooptic modulators. The approach is to avoid powders, and the attendent problems of powder handling, flow, packing, etc., and make use of polymerization condensation reactions to form extended networks with chemical linkage. Data are reported for the synthesis and low temperature processing routes for amorphous and polycrystalline ceramics.     

Pulsed laser deposition of perovskite relaxor ferroelectric thin films

Structural, dielectric and ferroelectric properties of thin films of La-doped lead zirconate titanate (PLZT) and sodium bismuth titanate-barium titanate (NBT-BT) perovskite relaxor ferroelectric have been investigated. PLZT films were deposited on Pt/Si substrates in oxygen atmosphere by pulsed laser deposition (PLD) and radio frequency (RF) discharge-assisted PLD, using sintered targets with different La content and Zr/Ti ratio, near or at the boundary relaxor ferroelectric. The films are polycrystalline with perovskite cubic or slightly rhombohedral structure. A slim ferroelectric hysteresis loop, typical for relaxors, has been measured for all film sets. Dielectric characterization shows a large value of capacitance tunability and low dielectric loss. However, common problems related to lead diffusion into the metallic electrode layer do not allow one to obtain high capacitance values, due to the formation of an interface layer with low dielectric constant. Lead-free NBT-BT thin films have been deposited on single crystal (1 0 0)-MgO substrates starting from targets with composition at the morphotropic phase boundary between rhombohedral and tetragonal phase. Films deposited by PLD are polycrystalline perovskite with a slight (1 0 0) orientation. Capacitance measurements were performed using interdigital metallic electrodes deposited on the film's top surface and showed high relative dielectric constant, on the order of 1300.     

Acetic Acid Based Sol-Gel PLZT Thin Films: Processing and Characterization

PLZT 4/65/35 thin films were prepared by the acetic acid based sol-gel route. The choice of lanthanum precursor, i.e., acetate or nitrate, influences the functional group content of formamide modified sols and the microstructure of the thin films. The lanthanum nitrate based PLZT thin film deposited on Si/SiO2/TiO2 /Pt/TiO2 substrate has a columnar perovskite grain structure, while the lanthanum acetate based one is characterized by a lead-silicon containing reaction layer beneath the platinum electrode. Although lead is depleted from the PLZT thin film the perovskite structure is retained by the use of the top layer with a large excess of PbO.     

EDTA-凝胶法制备PLZT超微粉的研究

以金属的硝酸盐和ＥＤＴＡ为原料，用ＥＤＴＡ－凝胶法制备均匀性好的ＰＬＺＴ超微粉。经ＦＴ－ＩＲ光谱、热重和差热分析、Ｘ射线衍射分析和透射电镜等方法研究表明：硝酸根离子可以加速ＥＤＴＡ－凝胶的热分解，仅在２５０℃时便有ＰＬＺＴ相生成，除ＰｂＯ外不出现其他中间相，经６００℃煅烧所得到的单一ＰＬＺＴ相超微粉，平均粒径为３５ｎｍ。