BBSZ掺杂对X波段移相器用LiZn铁氧体材料磁性能的影响

通过在Li-Zn铁氧体材料中掺入H3BO3-Bi2O3-SiO2-ZnO(BBSZ)玻璃相(1~4wt%),利用氧化物法陶瓷工艺合成Li-Zn铁氧体材料。在900℃烧结获得了符合要求的Li-Zn铁氧体材料。讨论了材料的微观结构以及磁性能,包括饱和磁化强度Ms、矫顽力Hc以及剩磁比Br/Bm。结果表明,BBSZ掺杂能显著降低材料的烧结温度,饱和磁化强度Ms随BBSZ掺入量的增加先增大而后略微减小,矫顽力Hc随BBSZ掺入量的增加先明显减小而后略微增加。当BBSZ掺入量为1.5wt%时,可以获得最佳的综合性能。     

SBNK玻璃掺杂对NiCuZn铁氧体材料稳定性的影响

采用传统的固相反应法制备NiCuZn铁氧体材料,通过添加不同含量的SiO2-B2O3-Na2CO3-K2CO3(SBNK)玻璃体系以及2.5 wt％的Bi2O3和0.2 wt％的Co2O3,研究了SBNK掺杂量对材料烧结密度、微观结构以及电磁性能的影响.研究表明,合适的掺杂量可减少材料气孔率和细化晶粒尺寸,同时磁导率有...     

CaCO3-SiO2掺杂对Sr0.44Ca0.08La0.48Fe11.3Co0.3O19-δ铁氧体微结构及磁特性的影响

采用传统氧化物陶瓷法制备Sr0.44Ca0.08La0.48Fe11.3Co0.3O19-δ铁氧体永磁材料,系统探究了CaCO3-SiO2组合添加对材料微结构及磁特性的影响.结果表明,适宜CaCO3-SiO2组合掺杂可促进烧结致密化,同时抑制晶粒长大,提高材料的剩磁Br和矫顽力Hc.在CaCO3掺杂量为0.5～0.9 wt％、SiO2掺杂量为0.25～0.40 wt％范围内,当CaCO3和SiO2掺杂量分别为0.6 wt％和0.3 wt％时,烧结样品晶粒分布均匀且致密,具有较优磁特性,剩磁、矫顽力、磁能积达到最大,分别为:Br=4120 G,Hcj=4031 Oe,Hcb=3677 Oe,(BH)max=4.19 MGOe.     

Bi_2O_3掺杂对NiCuZn铁氧体材料磁性能的影响

采用溶胶-凝胶(Sol-gel)法制备Ni0.2Cu0.2Zn0.6Fe2O4铁氧体材料。基于低温共烧铁氧体(LTCF)技术的要求,研究了掺杂Bi2O3对NiCuZn铁氧体材料的微结构和电磁性能的影响。结果表明,采用溶胶-凝胶法制备的NiCuZn材料,通过掺杂Bi2O3助烧剂,880℃低温烧结4h,已经生成所要的尖晶石相铁氧体;SEM显示随着Bi2O3的加入,NiCuZn铁氧体晶粒逐渐变大,生长均匀。在磁性能方面,添加3wt%Bi2O3时饱和磁化强度达到了77.03 A·m2/kg。Bi2O3在促进NiCuZn铁氧体烧结的同时,增大了材料的磁导率。     

掺杂SiO_2的低温烧结Ba_3(Co_(0.4)Zn_(0.6))_2Fe_(24)O_(41) Z型六角铁氧体材料

为了改善低温烧结Z型六角铁氧体Ba3(Co0.4Zn0.6)2Fe24O41材料的电磁性能,向体系中引入了SiO2,研究了掺杂SiO2对此材料在低温烧结时的显微结构和高频电磁性能的影响.发现SiO2的加入减小了晶粒的尺寸,使得其起始磁导率降低,但与此同时,SiO2的引入能够降低该体系在高频时的介电常数并提高其品质因数.     

Bi取代NiCuZn铁氧体的显微结构和电磁性能

分别用固相反应法制备了Bi取代NiCuZn铁氧体材料和二次球磨掺杂相同含量Bi2O3的NiCuZn铁氧体材料,研究了在900℃低温烧结下Bi取代和Bi掺杂对NiCuZn铁氧体材料的显微结构、电磁性能的影响。结果表明,Bi3+取代NiCuZn铁氧体材料的起始磁导率为152,Bi掺杂NiCuZn铁氧体材料的起始磁导率为148,且Bi取代NiCuZn铁氧体材料的致密性和均匀性优于Bi掺杂铁氧体材料,同时拥有更低的磁心损耗。     

ZnO含量及烧结温度对NiZn铁氧体性能和显微结构的影响

采用传统氧化物法制备了Ni0.49-xZn0.398+xCu0.112Fe2O4(x=0,0.014,0.026,0.038,0.05)铁氧体材料,研究了主配方及烧结温度对材料电磁性能和显微结构的影响。研究表明,ZnO含量对NiZn铁氧体材料的起始磁导率μi、饱和磁通密度Bs、Q值和比损耗系数tanδ/μi影响较大;当x=0.026时,NiZn铁氧体材料的饱和磁通密度最高;饱和磁通密度随烧结温度先升高后降低,当烧结温度为1100℃时,晶粒尺寸分布均匀、结构致密性好,其饱和磁通密度达到最大。在本研究中,最佳工艺参数为:x=0.026,烧结温度1100℃。     

V2O5掺杂对低温烧结MnZn功率铁氧体显微结构及性能的影响

采用氧化物陶瓷工艺制备低温烧结MnZn功率铁氧体材料,研究V2O5掺杂对材料显微结构、烧结温度、烧结密度、收缩率、磁导率、饱和磁感应强度及功耗特性的影响.结果表明,随V2O5掺杂量的增加,样品平均晶粒尺寸增大,材料烧结温度降低,收缩率增大,烧结密度、磁导率及饱和磁感应强度先增高后降低,功耗先降低后增高.配方采用MnCO3:38.85 mol％、ZnO:10.18 mol％、Fe2O3:50.97 mol％,基础添加Bi2O3:1 wt％并掺杂V2O5:0.5～0.7 wt％,可获得具有高饱和磁感应强度(Bs>380 mT,1.2 kA/m下测量)、低功耗(功率损耗Pcv<500 kW/m3(20℃,1 MHz,30 mT)、高磁导率(1000左右)的性能,显微结构致密,其烧结温度<950℃.     

高性能低温烧结NiCuZn材料ZL500的开发

介绍了一种应用于MHz下的高磁导率(μi=500)、高Q值(在1MHz下超过120)、低烧结温度(880℃)NiCuZn材料的开发。研究表明,引入适量的CuO并掺杂适量的V2O5和Co2O3可以促进晶粒的生长,从而降低烧结温度,并且可以获得高Q值;通过对原材料的选择,严格控制主配方和制备工艺获得了优良的材料性能。     

掺杂Bi2O3、Mn3O4、CO2O3、LiCO3对NiCuZn铁氧体材料性能的影响

为了提升叠层片式抗EMI滤波器用低温共烧NiCuZn铁氧体材料的性能,研究了Bi2O3、Mn3O4、Co2O3、LiCO3掺杂对NiCuZn铁氧体材料微观结构及电磁性能的影响。采用传统的氧化物法制备NiCuZn材料,对材料的主配方、助烧剂、掺杂进行适当的选择,采用适当制备工艺可达到良好效果,制备出优异性能的抗EMI滤波器用低温共烧NiCuZn铁氧体材料。     

烧结温度对注塑成型FeSiCr材料电磁性能的影响

采用注塑工艺压制生坯,在氮气气氛下、以不同温度(800?1300℃)烧结制备铁硅铬环形磁芯。测试了磁环的电磁性能、频谱特性和XRD谱,观察了磁环表面和截面的SEM形貌等。系统研究了烧结温度对密度、磁导率、频谱特性、物相、显微结构等的影响。结果表明,在900℃以下烧结,密度、显微结构和电磁性能没变。在1000℃烧结温度下,电磁性能最佳。1000℃以上烧结,密度升高,但是磁环内部出现另相和晶粒异常长大,导致电磁性能急剧下降。由于1000℃的烧结条件下,铁硅铬磁环有最佳低频电磁性能,为正在注塑研发铁硅铬相关产品提供指导。     

Normal sintering and electric properties of (K,Na,Li)(Nb,Sb)O3 lead-free piezoelectric ceramics

0.94(K₀₅Na_0.5)NbO₃?0.03LiNbO₃?0.03LiSbO₃ (KNLNS) lead-free piezoelectric ceramics were prepared by conventional mixed oxide route with normal sintering method. The samples were sintered at different temperatures with KNLNS powder atmosphere to prevent volatilization of alkali metal oxides at high temperature. The effects of sintering temperature on the density, structure and electric properties of KNLNS ceramics were studied. X-ray diffraction (XRD) results showed that the crystal structure of the crushed KNLNS ceramic powders were pure perovskite phase with tetragonal phase structure when sintered at T????1080°C. However a K₃Li₂Nb₅O₁₅ phase with tetragonal tungsten bronze structure began to appear when the sintering temperature was higher than 1080°C. The optimum sintering temperature was 1080°C which was determined by measuring the density of the samples. Scanning electron microscope (SEM) observation indicated that the sintering temperature had a great effect on the microstructure of the samples. The KNLNS ceramics under the optimum sintering temperature showed excellent electric properties: ???=?4.29 g/cm³, ?? _r?=?826, tan???=?0.049, d ₃₃?=?190 pC/N, k _p?=?0.30, and T _c?=?385°C. The results show that the KNLNS ceramics are promising candidate for lead-free piezoelectric ceramics.     

烧结温度对超低损耗锰锌铁氧体性能的影响

使用同一配方制备得到的锰锌铁氧体坯件分别在1360℃、1330℃、1300℃下采用平衡气氛法烧结,制备得到致密的锰锌铁氧体磁环。SEM结果表明,降低烧结温度有效地减小了晶粒尺寸,消除了晶粒内部气孔,改善了晶粒均匀程度,使晶界更为清晰。电磁性能测试表明,在三种温度烧结得到的锰锌铁氧体材料的起始磁导率μi没有显著差异;饱和磁感应强度Bs随烧结温度降低有小幅上升;总功率损耗随烧结温度的降低而下降;并且在1300℃烧结的铁氧体材料的功率损耗(100k Hz/200m T,100℃)很低,约为255k W/m~3。通过损耗分离证实,总功率损耗的改善主要是涡流损耗大幅降低所致。     

Low temperature sintering of Ba0.91Ca0.09Ti0.916Sn0.084O3 lead-free piezoelectric ceramics with the additives of ZnO and MnO2

The objective of this work is to lower the sintering temperature of Ba_0.91Ca_0.09Ti_0.916Sn_0.084O₃ (BCTS) ceramics without sacrificing the piezoelectric performance. The low-temperature sintering technique has been conducted to prepare the BCTS ceramics by adding two additives of ZnO and MnO₂. The ceramics endure a phase transition from a ferroelectric tetragonal phase to a pseudo-cubic relaxor ferroelectric with increasing MnO₂ content. The addition of ZnO and MnO₂ decreases the sintering temperature greatly, positively affecting their dielectric and piezoelectric properties. An enhanced electrical behavior of d ₃₃?～?495 pC/N, k _p?～?43.0 %, ε _r?～?5429, and tan δ?～?1.54 % has been observed in the ceramic with x?=?0.1 wt% when sintered at ~1315 °C. As a result, the method to dope two additives of ZnO and MnO₂ can effectively improve the piezoelectric properties of BaTiO₃-based ceramics sintered at a low temperature.     

Zn取代Ni2Y型六角铁氧体的微波吸收特性

采用陶瓷烧结方法制备了Ba2Ni2-xZnxFe12O22(x=0,0.8)六角铁氧体。X射线衍射(XRD)分析表明样品为单相Y型六角铁氧体,扫描电镜(SEM)观察显示样品形貌呈球状颗粒,直径约为500nm。用驻波比法在1~4GHz频率范围测量了样品的微波吸收率,发现Zn2 掺杂对Ni2Y型六角铁氧体的微波吸收性能影响很小,在频率2.4GHz,材料对微波均有较强的吸收峰,对厚度d=1.2mm的样品,吸收率达85%。     

Investigation on structural and electrical properties of BZT ceramics synthesized at low temperature

Abstract

Due to environmental concerns, lead free ceramics such as KNN- NBT and BT have growing interest in applications such as actuators and sensors. Among them Barium Zirconate Titanate (BZT) has become most attractive because it is derived from two perovskite lattice i.e. Barium Titanate (BaTiO₃) and Barium Zirconate (BaZrO₃). It has been reported that Zirconium substitution in titanium lattice enhances the material properties. In the present paper BZT was prepared using solid state route. By adding a mixture of Li₂CO₃ as a sintering aid, the sample could be sintered at 1150?°C having around 94% of the theoretical density. Prepared samples were then subjected to XRD analysis. X-ray diffraction revealed the formation of single phase material. It is observed that the electrical properties of such low-temperature sintered samples are comparable with BZT samples prepared via conventional sintering at a high temperature. It is also observed that the curie temperature shift towards room temperature for a samples sintered at low temperature.     

Effects of Glass Phase Additions and Stoichiometry on the Ba(Zn<Subscript>1/3</Subscript>X<Subscript>2/3</Subscript>)O<Subscript>3</Subscript> (<Emphasis Type="Italic">X</Emphasis> = Ta or Nb) Sinterability and Dielectric Properties

Ba(Zn_1/3X_2/3)O₃ materials where X = Ta or Nb (respectively named BZT and BZN) exhibit attractive properties suitable for applications in type I Multi Layer Ceramics Capacitors (MLCC). Nevertheless, to produce such components using Base Metal Electrodes such as copper, a significant reduction of their sintering temperature is required. The aim of this work is first to study the effects of glass phases additions and secondly the stoichiometry influence on the sintering temperature of BZT and BZN. It is shown for example, that our materials can be sintered in air at a temperature lowered by 450C when sintering agents (B₂O₃ with LiF) are combined with a slight non-stoichiometry. The sintered samples are characterised in terms of final density, microstructure and phase content and it was underlined that such modifications (additions and stoichiometry) does not affect the dielectric properties.     

The effect of TiO<Subscript>2</Subscript> and P<Subscript>2</Subscript>O<Subscript>5</Subscript> on densification behavior and properties of Anortite-Diopside glass-ceramic substrates

In this work the synthesis of anorthite-diopside glass-ceramics (GCs) was carried out via sintering and crystallization of glass powder compacts in the temperature interval 800°C and 950°C. Glass powder compacts with mean particle size of 2 μm were prepared. The effects of adding TiO₂ and P₂O₅ on the sintering behavior of glass powder compacts and on the properties of resultant glass-ceramics were studied. Mechanical, thermal, chemical and dielectric properties of sintered GCs were investigated with the aim to evaluate the potential of the GCs as substrate materials for microelectronics applications.     

烧结保温时间对KNN-LS-BF-0.15%Cu压电陶瓷性能的影响

采用传统的陶瓷制备工艺,在1 060℃下分别保温2 h、4 h和6 h,制备了{0.996[0.95(Na0.5K0.5)-NbO3-0.05LiSbO3]-0.004FeBiO3}+0.15mol%CuO(简称KNN-LS-BF-0.15%Cu)压电陶瓷,研究了烧结保温时间对陶瓷性能的影响。结果表明,过短的烧结保温时间并不能促成陶瓷晶粒的长成,但超过4 h后继续延长烧结保温时间对晶粒尺寸的影响不大;随着烧结保温时间的延长,KNN-LS-BF-0.15%Cu陶瓷的压电常数d33、机电耦合系数kp和介电常数εr先升高后降低,而介电损耗tanδ和机械品质因数Qm则随之下降;当烧结保温时间为4 h时,样品具有最佳的综合性能:d33=185 pC/N,kp=0.28,εr=1054.25,tanδ=2.1%,Qm=53.39。     

添加剂对AgSnO2复合粉末烧结体组织的影响

采用化学镀方法制备含微量添加剂CuO、Bi2O3的AgSnO2复合粉末。用压制-烧结-复压的方法进行烧结,用光学显微镜、扫描电镜观察烧结体的金相组织及复合粉末形貌。研究了微量添加剂CuO、Bi2O3对AgSnO2烧结性能和组织的影响。结果表明：不含添加剂的AgSnO2粉末烧结组织中存在黑色的网状形貌;微量添加剂CuO、Bi2O3有利于AgSnO2烧结致密化,CuO能显著提高烧结体的致密度,Bi2O3对于消除网状形貌效果明显;经化学镀银并复合添加CuO、Bi2O3所得到的复合粉末烧结后,其烧结体密度达9．44g／cm^3,且SnO2颗粒细小,均匀分布于银基体中。