以硝酸氧锆为锆源溶胶-凝胶合成PZT纳米晶的研究

以硝酸氧锆,钛酸四丁酯,醋酸铅为原料,乙二醇为溶剂,用改进的溶胶－凝胶技术,难过优化工艺条件制备了组成在准同型相界点附近的钙钛矿相球形颗粒状ＰＺＴ纳米晶（Ｚｒ／Ｔｉ＝５２／４８）实验中发现前驱物间的聚合反应使硝酸氧锆能很好地溶于乙二醇,通过溶胶的红外光谱分析给出了溶胶,凝胶形成的机理,通过Ｘ射线衍射分析,热重及差热分析,透射电镜显微镜分析对凝胶到ＰＺＴ纳米晶的形成过程及粉体性能进行了表征,实验证明     

湿化学方法制备Pb（ZrxTi1—x）O3陶瓷微粉的研究

以金属醇盐和硝酸盐为原料，按Ｐｂ（Ｚｒ０．５２Ｔｉ０．４８）Ｏ３＋５％（ｍａｓｓ０ＰｂＯ设计组成，采用改进的湿化学方法，严格控制共沉淀物生成，洗涤，分散液的选配及冷冻干燥条件；再经合理煅烧工艺，不需粉磨，制成化学组成均匀分布，不含有硬团聚体，具有单一钙钛矿晶相，高烧结活性的亚微米级Ｐｂ（ＺｒｘＴｉ１－ｘ）Ｏ３（ＰＺＴ）微粉。     

在ITO玻璃衬底上制备锆钛酸铅铁电薄膜

利用射频反应性溅射沉积技术在掺的Ｓｎ的Ｉｎ２Ｏ３导电透明膜衬底上制备了钙钛矿型Ｐｂ（Ｚｒ,Ｔｉ）Ｏ３（ＰＺＴ）铁电薄膜。研究了沉积参量与热处理工艺对铁电薄膜结构和性能的影响。运用Ｘ射线衍射、Ｘ射线光电子能谱和扫描电镜等技术,分析了薄膜的晶体结构、表面形貌和表面元素化学状态。测量了不同处理条件下薄膜的铁电性能。结果表明：在掺Ｓｎ的Ｉｎ２Ｏ３导电透明膜衬底上可以得到表面无裂纹,化学计量比符合要求的ＰＺ     

PZT薄膜的MOD制备及形成机理研究

采用金属有机物热分解（ＭＯＤ）工艺在Ｐｔ／Ｔｉ／ＳｉＯ２／Ｓｉ衬底上制备锆钛酸铅（ＰＺＴ）薄膜。ＸＲＤ分析显示薄结晶状态良好,无焦绿石相存在。ＡＥＳ测量表明：薄膜成分沿膜厚均匀分布,膜中无碳存在,表面不富含铅。分析了薄膜的形成机理,安性地解释了晶粒的生长过程。     

PZN-BT-PZT陶瓷的相结构与压电和介电性能研究

采用传统陶瓷工艺合成了（１－ｘ）（０．９４Ｐｂ（Ｚｎ１／３Ｎｂ２／３）Ｏ３－０．０６ＢａＴｉＯ３）－ｘＰｂ（Ｚｒ０．５３Ｔｉ０．４７）Ｏ３系陶瓷材料，结构分析表明，在ｘ〉０．３０时，可以得到纯钙钛矿相，在ｘ＝０．５０－０．６０，附近存在一个三方－四方共存的准同型相界，在此相界附近的压电，介电性能较好，同时还研究了退火处理对其介电，压电性能的影响，得到了平面机电耦合系数Ｋｐ＝６０％，压电系数ｄ３３＝     

Ti－Zr－N三元陶瓷调幅相的结构与成分分析

通过对高纯ＴｉＺｒ（Ｔｉ／Ｚｒ＝５０／５０，原子百分比）合金的高温氮化和高温退火制取了Ｔｉ－Ｚｒ－Ｎ三元系复合陶瓷实体材料。应用ｘ射线衍射（ＸＲＤ）、扫描及透射电子显微镜（ＳＥＭ，ＴＥＭ）、电子能量损失谱（ＥＥＬＳ）等方法分析研究了该（Ｔｉ，Ｚｒ）Ｎ复合陶瓷材料中调幅相的晶体学性质、显微结构特征及化学组成。     

合成三聚氯氰的氯化和聚合反应宏观动力学研究

利用非等温固定床反应器，研究了三聚氯氰合成的氯化和聚合反应宏观动力学，实验表明氢氰酸与氯气的氯化反应为气相均相反应，而氯氰的聚合反应为吸附在活性炭表面上的氯氰表面反应为控制步骤的气固催化反应。实验测得氯化反应的宏观反应动力学方程为对氢氰酸的一级反应，即（－ｒＡ）１＝２．４５×１０７ｅｘｐ（－２．９０×１０４／ＲＴ）ｃＡ测得聚合反应的宏观动力学方程为（－ｒＡ）２＝ｋ［ｐ３Ａ－ｐＲ／Ｋｐ］／［１＋ＫＡｐＡ＋ＫＲｐＲ］３ｋ＝４．０×１０７ｅｘｐ（－４．３５×１０４／ＲＴ）Ｋｐ＝６．７６×１０－２３ｅｘｐ（３．５２×１０５／ＲＴ）ＫＡ＝４．０×１０３ｅｘｐ（－３．３９×１０４／ＲＴ）ＫＲ＝１．０５×１０３ｅｘｐ（－５．０２×１０４／ＲＴ     

由压力波动判断气-固流化床中的流化类型

采用压力波动标准偏差判断散式流化和聚式流化，通过实验得出了聚式流化速度 ｕｈ的经验表达式，发现 ｕｈ／ｕｍ ｆ随颗粒的增大而减小，与［（ρｐ－ ρｇ／ρｇ）（ Ｒｅｐ）ｍ ｆ］０．４８成反比，并提出了产生聚式流化的条件为［（ρｐ－ ρｇ）／ρｇ］（ Ｒｅｐ）ｍ ｆ＞ ２０００     

Ti—Zr—N三元陶瓷调幅相的结构与成分分析

通过对高纯ＴｉＺｒ（Ｔｉ／Ｚｒ＝５０／５０，原子百分比）合金的高温氮化和高温退火制取了Ｔｉ－Ｚｒ－Ｎ三元系复合陶瓷实体材料。应用Ｘ射线衍射（ＸＲＤ）、扫描及透电子显微镜（ＳＥＭ，ＴＥＭ）、电子能量损失谱（ＥＥＬＳ）等方面分析研究了该（Ｔｉ，Ｚｒ）Ｎ复合陶瓷材料中调幅相的晶体学性质、显微结构特片及化学组成。     

先驱体法合成三元系Pb（Sc1／2Ta1／2）O3—PbZrO3—PbTiO3钙钛矿铁电陶瓷粉末

本文研究了采用不用先驱体ＳｃＴａＯ４＋Ｚｒ０．５３Ｔｉ０．４７Ｏ３（ＳＴ＋ＺＴ）和（Ｓｃ１２Ｔａ１２）０．２０Ｚｒ０．３８５Ｔｉ０．４１５Ｏ２（ＳＴＺＴ）以及采用ＳＴ＋ＺｒＯ２＋ＴｉＯ２与ＰｂＯ进行固相反应合成三元系Ｐｂ（Ｓｃ１２Ｔａ１２）０．２０－Ｚｒ０．３８５Ｔｉ０．４１５Ｏ３钙钛矿陶瓷粉末的合成机理。实验表明，两种先驱体均能与ＰｂＯ反应制得单相钙钛矿材料，合成过程中未发现焦绿石相。实验中发现，以ＳＴ＋ＺＴ为先驱体比ＳＴＺＴ先驱体更容易得到单相钙钛矿材料，其原因是ＺＴ先驱体对材料钙钛矿形成具有一定的促进作用。实验过程中发现试样随合成温度的变化有程度不同的膨胀现象，这种膨胀是采用先驱体法合成的钙钛矿粉末具有超细晶粒尺寸的主要原因。     

Effect of Switching Atmospheric Conditions during Crystallization on the Phase Evolution of Solution‐Derived Lead Zirconate Titanate Thin Films

The crystallization behavior of solution‐derived lead zirconate titanate (PZT) thin films in different atmospheric environments was studied using in situ X‐ray diffraction. The stability of the transient intermetallic Pt₃Pb phase and perovskite PZT is dependent on oxygen partial pressure during crystallization. Based on the relationship between oxygen partial pressure and the resultant phase stability of intermediate phases, a new route to produce PZT thin films was developed. The new route involves switching atmospheres during crystallization and is shown to mitigate the formation of the transient intermetallic Pt₃Pb phase and to promote the perovskite PZT phase. The route evidences a new and significant variable controlling film synthesis and film microstructure.     

Role of the PbTiO3 Seed Layer on the Crystallization Behavior of PZT Thin Films

The role of a highly crystalline and oriented lead titanate (PTO) seed layer on the subsequent phase and texture evolution of lead zirconate titanate (PZT) thin films is investigated in situ using X‐ray diffraction (XRD) during crystallization. Crystalline PTO seed layers were first prepared via a 2‐methoxyethanol route. Amorphous PZT with a Zr/Ti ratio of 52/48 was then deposited on the seed layer using the same synthesis route and subsequently crystallized in situ during XRD. During heating, a tetragonal‐to‐cubic transformation of the seed layer occurs prior to the formation of perovskite PZT. Subsequent nucleation of the crystalline PZT occurs in the cubic phase. Simultaneous to nucleation of PZT, development of a dominant 100 texture component was observed in the PZT phase of the thin films. The results indicate that 100 textured PTO nucleates 100 texture of PZT thin films during crystallization.     

Direct processing of PbZr0.53Ti0.47O3 films on glass and polymeric substrates

This work reports on direct crystallization of PbZr_0.53Ti_0.47O₃ (PZT) thin films on glass and polymeric substrates, using pulsed thermal processing (PTP). Specifically, xenon flash lamps deliver pulses of high intensity, short duration, broadband light to the surface of a chemical solution deposited thin film, resulting in the crystallization of the film. Structural analysis by X-ray diffraction (XRD) and transmission electron microscopy show the existence of perovskite structure in nano-sized grains (≤5 nm). Local functional analysis by band excitation piezoelectric spectroscopy and electrostatic force microscopy confirm the presence of a ferroelectric phase and retention of voltage-written polarization for multiple days. Based on structural and functional analyses, strategies are discussed for optimization of pulse voltage and duration for the realization of crystalline ferroelectric thin films. For ∼200 nm-thick PZT films on glass substrates, 500 μs-long pulses were required for crystallization, starting with 100 pulses at 350 V, 10 or 25 pulses at 400 V and in general lower number of pulses at higher voltages (resulting in higher radiant energy). Overall power densities of >6.4 kW/cm² were needed for appearance of peaks corresponding to the perovskite phase in the XRD. Films on glass processed at 350–400 V had a higher degree of 111-oriented perovskite grains. Higher applied radiant energy (through increased pulse voltage or count) resulted in more random and/or partially 001-oriented films. For ∼1 μm-thick PZT films on polymeric substrates, 10 to 25 250 μs-long pulses at voltages ranging between 200 to 250 V, corresponding to power densities of ∼2.8 kW/cm², were optimal for maximized perovskite phase crystallization, while avoiding substrate damage.     

铅/钡摩尔比对铅酸钡陶瓷薄膜电阻率的影响

铅酸钡(BaPbO3)导电薄膜是目前最有潜力的锆钛酸铅(lead zirconate titanate,PZT)铁电器件底电极替代材料之一.用溶胶-凝胶法在氧化铝(Al2O3)基片上旋涂成型BaPbO3薄膜.由于氧化铅(PbO)的高温挥发性,因此有必要研究薄膜中的铅/钡摩尔比与薄膜电阻率之间的关系.实验比较了常规热处理(conventional thermal annealing,CTA)和快速热处理(rapid thermal annealing,RTA)方式,用X射线衍射和能量散射X射线能谱研究了热处理方式和热处理制度对薄膜方阻的影响,分别得到了CTA和RTA热处理条件下BaPbO3薄膜的最低方阻性能,与CTA热处理相比,RTA热处理技术需要更高的热处理温度,因此,CTA热处理技术更为适合BaPbO3薄膜的合成.     

Fabrication of Pb(Zr,Ti)O3 thin films utilizing unconventional powder magnetron sputtering (PMS)

Pb(Zr,Ti)O3 (PZT) ferroelectric ceramic films exhibit highly superior ferroelectric, pyroelectric and piezoelectric properties which are promising for a number of applications including non-volatile random access memory devices, non-linear optics, motion and thermal sensors, tunable microwave systems and in energy harvesting (EH) use. In this research, a thin layer of PZT was deposited on two different substrates of Strontium Titanate (STO) and Strontium ruthenate (SRO) by powder magnetron sputtering (PMS) system. The preliminary powders, consisting of PbO, ZrO₂ and TiO_2, were manually mixed and placed into the target holder of the PMS. The deposition was performed at an elevated temperature reaching up to 600 °C via a ceramic heater. This high temperature is required for PZT thin film crystallinity, which is never achieved in conventional physical vapour deposition processes. The phase structure, crystallite size, stress-strain and surface morphology of deposited thin films were characterized using X-ray Diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM). The composition of the PZT thin films were also analysed by X-ray photoelectron spectroscopy (XPS). The mechanical properties of the thin films were evaluated with micro-scratch adhesive strength and micro hardness equipment. FESEM results showed that the PZT thin films were successfully deposited on both SRO and STO substrates. The surfaces of the coated samples were free from cracks, relatively smooth, uniform and dense. The profile of X-ray diffraction confirmed the formation of single-c-domain/single crystal perovskite phase grown on both substrates. The XPS analysis have shown that the PZT thin film grown by this method and that a target of PZT+10% PbO is a proper target for growing nominal PZT thin films. The adhesion strength and micro hardness results have confirmed the stability and durability of the thin film on the substrates, although higher values have been reported for thin film of PZT deposited on SRO surfaces.     

Effect of Nb Doping on the Microstructure of Sol—Gel-Derived PZT Thin Films

Aliovalent Nb doping (<10 at.%) of sol—gel-derived lead zirconate titanate (PZT) thin films was investigated with the intention of improving the ferroelectric properties. Nb addition was found to significantly alter the perovskite crystallization by stabilizing the transient pyrochlore phase, resulting in the retention of pyrochlore second phases and an increase in the perovskite lateral grain size and columnarity. The occurrence and composition of Zr-rich (surface) pyrochlore phases were found to depend on Nb concentration, annealing temperature, and Pb content. The observed changes in ferroelectric and dielectric properties as a function of Nb dopant addition were found to be strongly influenced by microstructural effects and the occurrence of pyrochlore, and hence the intrinsic effects of Nb incorporation in the perovskite lattice could not be directly ascertained.     

(SrZrO_3)_(10)(SrTiO_3)_(90)缓冲层对PZT结晶及性能的影响

采用Sol-gel法制备了PbZr0.52Ti0.48O3 (PZT)薄膜,并研究了(SrZrO3)10(SrTiO3)90((SZO)10(STO)90)缓冲层对PZT薄膜结晶和性能的影响.X射线衍射(XRD)结果表明:(SZO)10(STO)90缓冲层对PZT薄膜结晶有取向诱导作用,由(SZO)10(STO)90诱导的PZT薄膜有很强的(111)择优取向,缓冲层将PZT薄膜的取向度α由45.0%提高到了90.1%以上;PZT的(111)择优取向提高了薄膜的电性能,使剩余极化强度Pr从26.8 μC/cm2增大到38.8 μC/cm2.     

Effect of rare earth doping on sol-gel derived PZT thin films

We have studied the effect of rare earth dopants (Nd, Gd and Ce) on the phase formation behavior and electrical properties of sol-gel derived Pb_1.05(Zr_0.53Ti_0.47)O₃ thin films. In all these films the perovskite phase is obtained up to 5 at% doping and beyond that pyrochlore phase was found to coexist with the perovskite phase. Ce and Gd doping(1-2 at%) exhibited improved ferroelectric and dielectric properties as compared to the undoped PZT films. Nd doping (2 at%) was found to be effective to increase the retained switchable polarization of undoped PZT from 63% to 84%. The transition temperature of undoped PZT film was found to be reduced with Nd doping. The Nd doped films also exhibited typical relaxor behavior and a diffuse phase transition, characteristic of the relaxor material. Introduction of Nd into the PZT lattice probably introduces disorder in the B site of ABO₃ lattice which causes the observed relaxor behavior     

Rapid Microwave Annealing of Amorphous Lead Zirconate Titanate Thin Films Deposited by Sol‐Gel Method on LaNiO3/SiO2/Si Substrates

The heating behavior of LaNiO₃ (LNO) films on SiO₂/Si substrate heated by 2.45 GHz microwave irradiation in the microwave magnetic field was first investigated, and then amorphous Pb(Zr_0.52Ti_0.48)O₃ (PZT) thin films were deposited on LNO‐coated SiO₂/Si substrates by a sol‐gel method and crystallized in the microwave magnetic field. The crystalline phases and microstructures as well as the electrical properties of the PZT films were investigated as a function of the elevated temperature generated by microwave irradiation. The perovskite PZT films with a highly (100)‐preferred orientation can be obtained by microwave annealing at 700°C for only 180 s of total processing time, and have good electrical properties. The results demonstrated that conductive metal oxide LNO as a bottom electrode layer is an advantage for the crystallization of PZT thin films by microwave irradiation in the microwave magnetic field.