Ag2O掺杂对Li0.02(Na0.52K0.48)0.98Nb0.8Ta0.2O3无铅压电陶瓷电性能影响的研究

用传统的固相无压烧结法制备了Li0.02(Na0.52K0.48)0.98Nb0.8T0.2O3-xAg2O(0≤x≤0.1)无铅压电陶瓷,研究了Ag2O掺杂对陶瓷电性能的影响.研究发现,适当掺杂Ag2O能显著提高陶瓷的电性能,在1090℃的烧结温度下,当掺杂量为0.06时,陶瓷的压电性能最佳,d33、Kp、εr、Pr均达到最大(d33=229 pC/N,Kp=55.2％,εr=802,Pr=23 μC/cm2),矫顽场降到最低(Ec=12 kV/cm),应变达到2.0％.但Ag2O的添加使陶瓷的机械品质因数Qm由139.7降到了58.8,使介电损耗tanδ由1.38％增加到了2.7％.     

制备工艺对铌锑-锆钛酸铅系压电陶瓷性能的影响

由Nb5+,Sb3+置换锆钛酸铅的B位离子,制备了用作大功率水声换能器材料的铌锑-锆钛酸铅系压电陶瓷.采用固相法合成了0.02Pb(Sb1/2Nb1/2)O3-0.98PbZr1-xTixO3(x=0.44～0.49)粉体.通过X射线衍射及扫描电镜分析.研究了不同锆钛比和烧结温度对陶瓷的相组成、显微结构和介电、压电性能的影响.结果表明:当合成温度为900℃时,获得的粉体的主晶相为钙钛矿结构.当Zr/Ti摩尔比为51/47,烧结温度为1230℃时,各项性能达到最佳值,介电常数ε T 32/ε0为1945,介电损耗tanδ为0.019,压电常数d33为425pC/N,机电耦合系数Kp为0.65,Curie温度θc为352℃.铌锑-锆钛酸铅系压电陶瓷的烧结温度范围宽,具有较强的工艺操作性且θc高.     

K0.48Li0.02Na0.5(Nb1–xSbx)O3压电陶瓷的制备与性能EI北大核心CSCD

采用微波烧结法制备了锑掺杂改性K0.48Li0.02Na0.5NbO3(KLNN)压电陶瓷,研究了锑掺杂量(x=0,0.02,0.04,0.06,0.08)对陶瓷的微观结构、表面形貌、介电性能、压电性能和铁电性能的影响。结果表明:在掺杂范围内,各组分的陶瓷样品均形成了单一的钙钛矿结构,结晶良好,晶粒均匀,说明金属锑在KLNN晶格中可以形成均匀固溶体,改善了KLNN基无铅压电陶瓷的微观结构,提高了其压电性能和铁电性能。在x=0.06时,K0.48Li0.02Na0.5(Nb0.94Sb0.06)O3陶瓷样品的Curie温度介电常数峰(εr)、单向电致应变(ε)、压电系数(d33)均达到最大值,分别为εr=5557,ε=0.08%,d33=208 pC/N。     

(Ba0.85Ca0.15)(Ti0.90Zr0.06Sn0.04)O3-Fe2O3无铅压电陶瓷的性能研究

采用固相法制备了(Ba0.85Ca0.15) (Ti0.90Zr0.06Sn0.04)O3-xmol％Fe2O3(简写为BCTZS-xFe)无铅压电陶瓷.研究了不同掺杂量对该陶瓷的显微结构、介电、铁电及压电性能的影响.结果表明,所有样品均具有单一的钙钛矿结构,少量掺杂能使晶粒长大,提高电性能.在x=0.025时,具有最佳的综合电性能,压电常数d33 =515 pC/N,机电耦合系数kp=48.2％,机械品质因数Qm =182,2Pr=18.2 μC/cm2,2Ec =4.3 kV/cm,介电常数εr=5175.     

锰掺杂对PNW-PMS-PZT压电陶瓷结构和性能的影响

采用传统陶瓷工艺制备了Pb(Ni1/2W1/2)O3-Pb(Mn1/3Sb2/3)O3-Pb(Ti，Zr)O3-xMnO2压电陶瓷，分析了经1150℃烧结2h制备的陶瓷样品的相结构组成。实验结果表明：所有陶瓷样品均为钙钛矿相，未发现其它晶相。随着锰掺杂量的增加，陶瓷晶粒逐渐长大。研究了不同剂量的锰掺杂对压电陶瓷介电和压电性能的影响。结果表明：随着锰掺杂量的增加，材料逐渐变“硬”，当MnO2掺杂量少于0．2％(按质量计，下同)时，相对介电常数εr、压电常数d33和机械品质因数Qm逐渐增加，介电损耗tanδ减小；当MnO2掺杂量多于0．2％时，εr、d33和Qm逐渐降低，tanδ增加。随着锰掺杂量的增加，机电耦合系数kp和Curie温度θc逐渐减小。MnO2掺杂量为0．2％的压电陶瓷适合制作大功率压电陶瓷变压器。其压电性能为：εr=2138，tanδ=0．0058，kp=0．613，Qm=1275，d33=380pC／N和θc=205℃。     

Sr、Mn离子掺杂PMS-PZT压电陶瓷相组成与性能研究

针对聚焦超声换能器用压电陶瓷,采用传统的固相法制备Pb1.04(Mn1/3 Sb2/3)0.05 Zr0.47 Ti0.48 O3+x％SrCO3+y％MnO2(x+y=0.3)(PMS-PZT)三元系压电陶瓷.使用正交实验分析方法研究添加不同比例的Sr、Mn离子后PMS-PZT压电陶瓷电学性能的变化.讨论了在准同型相界(MPB)随着掺杂元素相对含量的改变对压电陶瓷的相对介电常数εr、机电耦合系数kp、机械品质因数Qm和压电常数d33的影响.通过研究发现:在900℃煅烧,1180℃烧结保温2 h,当x=0.15时,三方相和四方相共存且三方度最大,得到综合性能优良的压电陶瓷材料:密度 ρ=7.84 g/cm3、压电常数d33=336 pC/N、机械品质因数Qm=1889、机电耦合系数kp=0.63、相对介电常数εr=1479,采用此工艺制备的压电陶瓷完全满足高强度超声换能器用的压电材料.     

Pb 1-xSrx(Mn1/3Sb2/3)aZrbTicO3三元系压电陶瓷的压电和介电性能

对Pb 1-xSrx(Mn1/3Sb2/3)aZrbTicO3+0.2%(质量分数)CeO2 (PMS-PZ-PT)三元系压电陶瓷的烧结温度(1 150～1 225 ℃)和Sr2+取代量(摩尔分数0～8%)进行了系统研究. 通过XRD图谱计算的晶格参数说明Sr2+取代Pb2+后, 晶胞更趋于各向同性且产生收缩, 从而改善样品的性能. 实验结果表明 当x=0.02时, 在1 200 ℃, 2 h条件下烧结, 能获得优良的综合性能εr =1 461, tanδ=0.003 8, Kp=0.63, Qm=1 321, d33=409×10-12 C·N-1, 可以满足超声马达和压电变压器等应用方面的要求.     

Ba掺杂对Pb(Zr,Ti,Sb)O_3压电陶瓷Curie温度与压电性能的影响

用传统固相法制备了组成为0.98Pb1.0–xBaxTi0.48Zr0.52O3–0.02PbSbO3(x=0.18～0.24)的Ba掺杂Pb(Zr,Ti,Sb)O3(PSZT)压电陶瓷。通过X射线衍射和Raman光谱研究了Ba掺杂PSZT陶瓷的结构,并测量和分析了Ba掺杂对PSZT压电陶瓷的Curie温度和压电性能的影响。结果表明:Ba掺杂影响PSZT陶瓷中四方相和三方相的转化过程、两相比例、晶粒大小并导致四方相的晶格畸变。随Ba含量(x)从0.18增加到0.24,PSZT陶瓷的Curie温度从189℃几乎线性下降到141℃;当Ba掺杂量为0.22时,PSZT陶瓷的Curie温度为156℃,压电应变常数d33为578pC/N,机电耦合系数Kp为0.63,机械品质因数Qm为37.3。     

不同氧化物掺杂对KNN无铅压电陶瓷性能的影响

为了获得压电性能高、稳定性好的无铅压电材料,利用传统固相烧结法制备(Na0.5K0.5)NbO3-(Bi0.5 Li0.5)TiO3-BaZrO3(简称KNN-BLT-BZ)无铅压电陶瓷.通过掺杂不同的氧化物,研究了不同氧化物掺杂对KNN-BLT-BZ无铅压电陶瓷性能的影响.实验表明,利用Ni2O3进行掺杂所得陶瓷的压电及铁电等性能最优:d33=265 pC/N,Qm=109,kp=0.34,tanδ=0.026,Pr=22.4μC/cm2,Ec=1.37 kV/mm,并且具有较高的居里温度(253℃);Fe2O3掺杂则可以明显提高陶瓷应变,促进晶粒长大,提高Qm、d33和室温下εr,降低室温下介电损耗;ZnO掺杂会降低压电陶瓷介电损耗,提高损耗的温度稳定性;掺杂Ag2O后会使陶瓷烧结温度提高.     

(K0.45+xNa0.55-x)0.98Li0.02(Nb0.77Ta0.18Sb0.05)O3-0.05BaZrO3无铅压电陶瓷的工艺对性能的影响

采用传统固相反应烧结法,以(K0.45+xNa0.55-x)0.98Li0.02(Nb0.77 Ta0.18 Sb0.05)O3-0.005BaZrO3无铅压电陶瓷为研究对象,研究K/Na比例、粉体合成温度、烧结温度、极化工艺条件对压电陶瓷性能的影响,以及退火温度和老化时间对材料性能稳定性的影响.结果表明:该体系陶瓷粉体的合成温度为850℃.烧结温度为1130℃,x=0.04时陶瓷的压电常数d33可达372 pC/N,机电耦合系数kp达0.465.合理的极化条件为极化电压4 kV/mm,极化时间25min,极化温度120℃.压电陶瓷在125℃下具有较好的温度稳定性,但时间稳定性较差,放置300 d后压电常数才能稳定.     

Li2CO3掺杂对0.2PMN-0.8PZT陶瓷的影响

利用铌铁矿预产物合成法,研究不同温度烧结下Li2CO3掺杂对0.2 PMN-0.8PZT压电陶瓷(简称PLC)的相结构和电性能的影响。X射线衍射(XRD)和扫描电镜(SEM)的分析结果表明,掺杂LiCO3的0.2PMN-0.8PZT压电陶瓷经不同温度煅烧后,所有陶瓷样品的相组成均为纯钙钛矿相,并随着烧结温度的升高,PLC的相结构有由四方相向菱方相转变的趋势。通过0.2PMN-0.8PZT压电陶瓷掺杂LiCO3煅烧后的微观形貌、介电常数、压电性能、铁电性能的分析,发现经1200℃烧结的样品的介电和压电性能最佳:介电常数(εr)为38512,室温压电常数(d33)为300 pC/N,剩余极化强度(Pr)为31.3 C/cm2,矫顽电场(Ec)为7.5 kV/cm。     

Preparation and photocatalytic performance of TiO2/PbTiO3 fiber composite enhanced by external force induced piezoelectric field

In this paper, anatase TiO₂ nanoparticles (14 nm) were coated on the surface of piezoelectric PbTiO₃ single crystal fibers by a secondary hydrothermal method, thus a p-n junction was formed at the interface between TiO₂ and PbTiO₃. The PbTiO₃ fibers were exposed to an external force (by ultrasound) to generate a dynamic piezoelectric electric field in the crystal, which incessantly separates the carriers and improves the photocatalytic efficiency of TiO₂. When the ultrasonic frequency is 40 kHz, the TiO₂/PbTiO₃ fibers have the highest photocatalytic degradation efficiency (96%) for methylene orange (MO), which is up to 60% improvement compared to TiO₂ nanoparticles.     

Sodium‐potassium niobate nanorods with various crystal structures and their application to nanogenerator

(Na_1?xK_x)NbO₃ (NKN) nanorods with an orthorhombic (OR) structure, a rhombohedral (RH) structure, or a polymorphic phase (PP) structure, which contains both OR and RH structures, are prepared. The presence of RH and PP NKN nanorods is explained by the existence of OH^? defects at the O^2? sites of the NKN nanorods. The PP NKN nanorods grown on a Nb⁵⁺‐doped SrTiO₃ substrate show the largest piezoelectric strain constant of 175 pm/V because they have more directions for dipole rotation than OR and RH NKN nanorods. Piezoelectric nanogenerators (NGs) are synthesized using composites consisting of NKN nanorods with various structures and polydimethylsiloxane. The largest open‐circuit output voltage is 35 V, and the short‐circuit current is 5.0 μA, which are obtained using the NG containing 0.7 g of PP NKN nanorods. Moreover, this NG shows a maximum output power of 16.5 μW for an external load of 10.0 MΩ.     

压电材料的研究和应用现状

简要介绍了压电材料的发展历史,详细叙述了压电陶瓷、压电单晶、压电复合材料及压电聚合物的发展状况,并对压电材料对日常生活的影响及其目前的研究热点做了概括。     

掺BaT3iO对（1-x）NBT-xBaTiO3系陶瓷材料压电性能的影响

测试了各组成点样品的压电性能,分析BaTiO 的掺入对(1-x)NBT-xBaTiO 系陶瓷材料压电性能的影响。实验结果表明:与PZT基含铅压电陶瓷相似,材料在准同型相界组成范围内压电性能最佳。     

Enhanced piezoelectricity and temperature stability in LaFeO3-modified KNN-based lead-free ceramics

(0.96-x)K_0.48Na_0.52NbO₃-0.04Bi_0.5Na_0.5ZrO₃-xLaFeO₃ ceramics (abbreviated as KNN-BNZ-LF1000x) with enhanced piezoelectric performance and temperature stability were prepared by the conventional solid-state sintering method. It was found that the incorporation of LaFeO₃ gradually shifted the O-T phase boundary toward room temperature, while maintaining the Curie temperature above 300°C. The optimal piezoelectricity was found at x = 0.006, with relatively high piezoelectric constant d₃₃ of 345 pC/N as well as a high level of unipolar strain (0.126% at 3 kV/mm). Benefiting from the diffused phase transition induced by appropriate amount of LaFeO₃ content, the KNN-BNZ-LF6 sample possessed greatly enhanced the temperature stability of , which varied less than 8% in the temperature range of 20°C-100°C.     

Effect of poling on piezocatalytic removal of muti-pollutants using BaTiO3

The BaTiO₃ powder was prepared via a solid-state reaction route. It was studied for the degradation of bacterial cells, dye, and pharmaceuticals waste using ultrasonically driven piezocatalytic effect. The bacterial catalytic behavior of poled BaTiO₃ was remarkably increased during ultrasonication (10% E coli survival in 60 minutes). The structural damages were illustrated using scanning electron micrographs of bacterial cells which demonstrated morphological manifestations under different conditions. Methylene blue (MB dye), ciprofloxacin and diclofenac were also cleaned using the piezocatalytic effect associated with the poled BaTiO₃ powder. Around 92, 85, and 78% of degradations were observed within 150 minutes duration for methylene blue, ciprofloxacin, and diclofenac, respectively.     

Electrocaloric behavior and piezoelectric effect in relaxor NaNbO3-based ceramics

We firstly reported the electrocaloric properties in relaxor (1−x−y)NaNbO₃–yBaTiO₃–xCaZrO₃ ceramics, and high electrocaloric effect (∆T ~0.451 K and∣∆T/∆E∣~0.282 Km/MV) can be realized in the ceramics (x = 0.04 and y = 0.10) under low temperature and low electric field. Relaxor behavior of NaNbO₃ ceramics can be found by doping both BaTiO₃ and CaZrO₃. In addition, optimized piezoelectric effects (d₃₃ ~235 pC/N and d₃₃* ~230 pm/V) can be observed in the ceramics (x = 0.04 and y = 0.10) due to the involved morphotropic phase boundary (MPB). Excellent piezoelectric effect (ie, d₃₃~330 pm/V at 41°C, and d₃₃*~332 pm/V at 60°C) can be found because of the characteristics of MPB. Good temperature reliability of piezoelectric effect can be shown because of both MPB and relaxor behavior. We believe that the ceramics with high electrocaloric effect and good piezoelectric effect can be considered as one of the most promising lead-free materials for piezoelectric devices.     

Excellent thermal stability and aging behaviors in BiFeO3-BaTiO3 piezoelectric ceramics with rhombohedral phase

BiFeO₃-BaTiO₃ (BF-BT) solid solutions are lead-free candidates for high-temperature piezoelectric applications. BF-BT ceramics with compositions near the morphotropic phase boundary (MPB) separating rhombohedral (R) and pseudo-cubic (PC) phases were fabricated by the conventional high temperature sintering method, and their thermal stability and aging properties were studied in detail. BF-BT ceramics with rhombohedral (R) phase show much better thermal stability and aging properties than those with pseudo-cubic (PC) or coexistence of PC and R phases. The thermal degradation and aging rates of BF-BT ceramics with R phase are on the order of 1% and 1.2% per decade, respectively. X-ray diffraction results reveal that the domain state of poled rhombohedral BF-BT ceramics is stable up to its Curie temperature, which is responsible for the high thermal stability. The Rayleigh analysis shows that the low aging rate is attributed to the low domain wall contribution to the overall piezoelectric response. The high thermal stability and low aging rates indicate that the lead-free BF-BT ceramics with R phase are potential candidates for sensor and transducer applications over a broad temperature range.