锆钛酸钡薄膜材料制备研究进展

综述了磁控溅射、脉冲激光沉积、sol-gel法制备锆钛酸钡(简称BZT)薄膜的研究现状,及其制备工艺参数与显微结构、介电性能的关系,提出了制备BZT薄膜材料需要解决的工艺和理论问题。     

锆钛酸钡掺杂改性研究进展

综述了锆钛酸钡(BaZrxTi1–xO3,简称BZT)材料的掺杂种类以及掺杂对晶粒尺寸、相变温度、介电非线性和介电弛豫的影响等方面的最新研究进展,提出了研究中在掺杂与结构等方面需要解决的一些问题。     

激光烧结锆钛酸钡压电陶瓷

报道了采用激光烧结技术制备锆钛酸钡(BZT)压电陶瓷的研究。用常规方法制备了锆钛酸钡粉料，采用CO2激光直接烧结锆钛酸钡坯材，最大激光功率150 W，扫描转速1440 rad/min，烧结时间10 min;对陶瓷样品介电频谱与谐振频谱的测量显示了锆钛酸钡的压电特征;比较了传统高温炉烧结与激光烧结陶瓷样品的高温介电谱线，激光烧结陶瓷样品居里温度有所提高;测得介电常数和压电常数分别为1563 pC/N和45pC/N;X射线衍射(XRD)谱图显示(111),(002)衍射峰相对强度增强;陶瓷样品表面的显微照片显示了晶粒生长的形貌。激光烧结可以作为功能陶瓷烧结的方法之一。     

PLD法制备高介电调谐率的纳米晶BZT薄膜

用脉冲激光沉积工艺制备了Ba(ZrxTi1-x)O3(x=0.25,0.30简称BZT25和BZT30)介电薄膜。在650℃原位退火10 min,薄膜为(111)取向柱状生长的晶粒,取向度分别为0.45和0.75。BZT25和BZT30薄膜的平均晶粒尺寸分别为50 nm和60 nm。在室温、1 MHz和3×105 V/cm条件下,BZT25的最大εr和调谐率分别达到563和65%,BZT30的最大εr和调谐率分别达到441和57%。薄膜为(111)取向生长,主要是基于薄膜与底电极Pt界面层立方相结构Pt3Ti的诱导,即(111)Pt3Ti和(111)BZT的晶格匹配。     

35kV备用电源进线断路器BZT装置拒动故障分析

本文阐述了35kV备用电源进线断路器BZT装置的动作原理,分析了BZT装置拒动故障的原因。     

Gd_2O_3掺杂对BZT基陶瓷结构和介电性能的影响

以碳酸钡、二氧化钛、二氧化锆等为主原料,以氧化钆为掺杂剂,采用传统固相法分别于1 250,1 280,1 300,1 330℃下制备了BaZr_(0.1)Ti_(0.9)O_3(BZT)+x Gd_2O_3(0≤x≤0.7%)陶瓷样品。XRD结果表明,Gd~(3+)掺杂后的陶瓷样品主晶相不变,均为钙钛矿结构。SEM结果表明,随着Gd3+掺杂量的增加,陶瓷的晶粒尺寸先减小后增大。陶瓷样品的体积密度和介电常数在x=0.2%,0.6%时出现较高值,介质损耗tanδ随Gd~(3+)掺杂量的增大呈减小趋势。Gd_2O_3掺杂改善了BZT陶瓷的介电温度特性,具有一定的移峰与压峰的作用。     

锆钛酸铅铁电薄膜的制备及光伏特性研究进展

介绍了铁电材料光伏效应的研究背景,指出了锆钛酸铅铁电薄膜光伏特性的研究意义。分析、归纳了锆钛酸铅铁电薄膜电极、膜厚和退火制度(退火温度、退火时间和退火气氛)等工艺参数与所制样品的界面层厚度、肖特基势垒以及取向的关系,综述了这些工艺参数对锆钛酸铅铁电薄膜光伏特性影响的研究现状,提出了锆钛酸铅铁电薄膜光伏特性研究中亟待解决的问题。     

烧结温度对锆钛酸钡钙陶瓷微结构及储能特性的影响

采用溶胶-凝胶法制备锆钛酸钡钙粉体,通过常压烧结制备锆钛酸钡钙陶瓷(Ba_(0.85)Ca_(0.15)Ti_(0.90)Zr_(0.10)O_3),借助XRD、扫描电镜、阻抗分析仪、铁电综合测试仪等表征手段系统研究了烧结温度对其微结构、电性能以及储能特性的影响。结果表明:较高的烧结温度有利于获得致密性好、晶粒尺寸较大的锆钛酸钡钙陶瓷;相对于1330℃,1430℃下制备的锆钛酸钡钙陶瓷的剩余极化强度、相对介电常数均更高,而介电损耗更低,但烧结温度为1330℃时制备的锆钛酸钡钙陶瓷的储能密度以及储能效率均优于烧结温度为1430℃时制备的样品。     

氢化钙还原二氧化锆制取锆粉

锆粉由于它的特性(良好的吸气性能、易燃、燃烧热值高等),在电真空工业,火药、特种燃料以及闪光灯泡制造等多方面得到了广泛的应用。冶金工业也通过粉末冶金的途径,用锆粉制备各种锆材和锆器件。锆粉的使用性能取决于它的化学成份和物理性质,此两方面的性质直接受制造锆粉方法的影响。为了制得适合干各种特殊用途的锆粉,人们对制造锆粉的方法进行了大量的广泛的研究工作,文献上的有关报导也屡见不鲜,归纳起来大致可分为如下三类;氢化法、金属热还原法和电解法。氢化法:是将块状的或粗颗粒的金属锆(如,海绵锆、电解锆晶体等)在氢气气氛下,加热至300～400℃,使之氢化成为氢化锆,利     

电真空锆粉化学分析

总锆量及活锆量的测定分析步骤将清洁之瓷坩埚(10毫升)连盖移入高温炉中,在800～850℃灼烧半小时,取出坩埚移入干燥器中冷却至室温,称量至恒重。用已知重量的10毫升瓷坩埚,称取试样1克盖上坩埚盖,外面套上一个大瓷坩埚,在800～850℃的高温炉中灼烧1小时(使金属锆氧化为氧化锆)取出稍冷,移入干燥器中,冷却至室温,用称取试样时相同天秤和砝码称量至恒重。锆的百分含量按下式计算:     

Structural characterization and thermoluminescence studies of UV irradiated and Eu3+ activated BaZr0.25Ti0.75O3 powders

Appropriate amount of dopant enhances the luminescence intensity of host material. Inspired by the encouraging electrical properties of perovskite materials, we report on some optical features of Eu³⁺ activated BaZr_xTi_(1−x)O₃(BZT) powders synthesized by solid state reaction technique (SSRT) that usually produces particles with comparatively bigger size. However, we have succeeded in obtaining particles of smaller size with this technique. The effects of adding Eu³⁺ to BZT phosphor have been studied in terms of XRD, FESEM, HRTEM, and UV–vis absorption spectroscopy. The X-ray diffractograms ascertain the formation of BZT with single phase while FESEM and HRTEM help in morphological analysis of prepared samples. The thermoluminescence (TL) glow curves for BZT:Eu³⁺are compared with respect to irradiation time and dopant concentration. The TL intensity is observed to be more for samples irradiated for longer time. It implies that irradiation time is an effectual and practical way to enhance TL intensity. The TL glow curves are deconvoluted using computerized glow curve deconvolution (CGCD) method. The kinetic parameters, which play vital role in characterizing a particular phosphor material, have been calculated and presented for BZT:Eu³⁺.     

Enhancement-mode In0.53Ga0.47As metal-oxide-semiconductor field-effect transistors with sol–gel processed gate dielectrics

Enhancement-mode In_0.53Ga_0.47As n-type metal-oxide-semiconductor field-effect transistors (MOSFETs), with barium zirconate titanate (BZT) and titanium dioxide (TiO₂) high-κ materials prepared via the solution–gelation process as gate dielectrics, have been fabricated. The dielectric constants of BZT and TiO₂ are 6.67 and 19.3, respectively. The In_0.53Ga_0.47As MOSFET with TiO₂ exhibits better electrical characteristics than the In_0.53Ga_0.47As MOSFET with BZT. These characteristics include higher maximum drain current density, higher maximum transconductance, and smaller subthreshold swing.     

Block Z transform and its application to FIR filtering

The block Z transform (BZT) is presented. It is shown that the BZT, used with the modified Fermat number transform (MFNT), is very efficient for FIR filtering of a long impulse response. The BZT takes advantage of the number theoretic transforms (NTTs), namely, the computational efficiency, and overcomes use of the restrictions on the NTTs, namely, the restriction on the length of the impulse response     

ZrO2掺杂对Ba(Zn1/3Ta2/3)O3陶瓷介电性能的影响

采用固相反应烧结法制备了ZrO2掺杂的Ba(Zn1/3Ta2/3)O3微波介质陶瓷,研究了陶瓷的烧结特性和介电性能。结果表明,ZrO2掺杂能有效降低Ba(Zn1/3Ta2/3)O3陶瓷的烧结温度,改善陶瓷的微波介电性能。当x(ZrO2)=4%时,Ba(Zn1/3Ta2/3)O3陶瓷致密化烧结温度由纯相时的1 600℃降至1 300℃,同时陶瓷材料的微波介电性能达到最佳值,即介电常数εr=34.79,品质因数与频率的乘积Q×f=148 000(8GHz),谐振频率温度系数τf=0.3×10-6/℃。     

Zn掺杂对BST薄膜介电调谐性能的影响

用sol-gel法在Pt/SiO2/Si基片上制备了未掺杂和掺杂Zn的钛酸锶钡(BST)薄膜。用XRD对BST薄膜进行了物相分析,研究了Zn掺杂对薄膜的表面形貌和介电调谐性能的影响。结果表明:室温下,随着Zn加入量的增加,BST薄膜的介电常数减小,介质损耗降低,介电调谐量增加。x(Zn)为0.025的BST薄膜具有最大的优越因子(FOM),其值为29.28。     

Enhanced Piezoelectric Properties and Tunability of Lead-Free Ceramics Prepared by High-Energy Ball Milling

Zirconium-doped barium titanate Ba(Zr_0.15Ti_0.85)O₃ lead-free ceramics (hereinafter referred to as BZT) were synthesized using the solid-state reaction method by adopting the high-energy ball milling technique. Nanosized BZT powders resulted from high-energy ball milling, which in turn enhanced the dielectric and piezoelectric properties of the ceramics. A single-phase perovskite structure free from secondary phase peaks was observed for sintered BZT samples, and a relative density of ～94% of the theoretical density was achieved. The electric-field-induced polarization-current data indicate the ferroelectric nature of the samples. Unipolar strain as high as 0.12% was realized for the ceramics sintered at 1350°C, indicating their potential for use in actuator applications. Very high tunability of >70% for these ceramics is also reported.