CuCr_(1-x)Mg_xO_2(0≤x≤0.09)薄膜的光电性能

采用射频磁控溅射方法,在石英衬底上制备Mg掺杂的CuCrO2薄膜。通过XRD、紫外吸收光谱及电学性能的测量表征该系列薄膜样品的结构与光电性能。结果表明:退火处理后所有薄膜样品的结晶性良好,均为3R型铜铁矿结构;薄膜的电导率随掺杂量的增加而增大。当x=0.09时,样品的室温电导率可达6.16×10-2S/cm,比未掺杂的CuCrO2提高近400倍,且霍耳测试表明所制备的薄膜为p型导电体。电导率随温度变化关系表明:薄膜样品在200～300K的温度范围内均很好地符合Arrhenius热激活规律;当x=0.09时,最低激活能仅为0.034eV。薄膜的可见光透过率与光学带隙宽度均随掺杂量的增加而减小。     

p型宽带隙半导体CuAl_(1-x)Fe_xO_2的光电性能研究

采用固相反应合成了CuAl1-xFeO2单相多晶材料,系统报道了该系列样品的X射线衍射(XRD)、紫外吸收光谱以及电学性能的测量.结果表明,Fe3+取代CuAlO2中的Al3+,不改变材料的晶体结构.随着掺杂量的增加,材料的光学带隙宽度逐渐减小,导电性能明显提高.当x=0.10时,样品的室温电导率达到3.38×10-1 S·cm-1;所有掺杂样品的电导率随温度变化曲线在近室温区,很好地符合Arrhenius关系,其热激活能为20～32 meV;Hall系数均为正值,表明所有样品都为P型半导体.     

V掺杂对Bi_(3.25)La_(0.75)Ti_3O_(12)层状结构铁电陶瓷电性能的影响

用高温固相烧结法制备了V~(5+)掺杂的Bi_3.25La_0.75Ti_3O_(12)(BLT)层状结构铁电陶瓷.利用XRD对Bi_3.25La_0.75Ti_(3-x)VxO_(12+x/2)(BLTV-x)材料结构进行了晶相分析,结果表明所制备的陶瓷均具有单一的正交相结构.样品的介电常数温度谱显示:V~(5+)掺杂提高了材料的介电常数,x=0.03时介电常数最大,但样品的居里温度并没有发生大的变化.样品的介电损耗谱表明:由于V~(5+)掺入,由氧空位引起的样品介电损耗被极大的压制,在x=0.06时损耗最小.通过对材料的直流电导与温度关系的Arrhenius拟合,分析了样品的导电机理,结果显示V~(5+)的掺杂大大降低了材料中氧空位的浓度,使得陶瓷样品的电性能得到了很好的改善.     

铜模喷铸Fe_(100-x)Ga_x(15≤x≤30)合金的磁致伸缩

采用铜模喷铸法,制备Fe100-xGax(x=15,19,23,27.5,30)合金。实验结果表明铜模喷铸有利于改善低Ga(15≤x<23)Fe100-xGax合金的磁致伸缩,却大幅降低了高Ga(23≤x≤30)Fe100-xGax合金的磁致伸缩。以Fe81Ga19和Fe72.5Ga27.5合金为例,喷铸态Fe81Ga19样品的饱和磁致伸缩比800℃淬火态提高了7%;而喷铸态Fe72.5Ga27.5样品的饱和磁致伸缩为6.1×10-5,仅是800℃淬火态的60.4%。此外,淬火态Fe72.5Ga27.5样品的饱和磁化强度为131.21A·m2·kg-1,也高于喷铸态(126.21A·m2·kg-1)。     

MB2镁合金SiO2基陶瓷涂层的性能

采用热化学反应法在MB2镁合金上制备了SiO_2基陶瓷涂层。并从微观结构、抗热震性、耐磨和耐蚀性能等方面测试涂层性能。试验结果表明:涂层中有新相MgMnSiO_4生成,涂层与基体结合强度较高,耐磨和耐腐蚀性能优异。     

SrCO_3掺杂La_2Ti_2O_7陶瓷的电性能

通过固相反应合成法制备了La_2Ti_2O_7陶瓷,研究了SrCO_3掺杂对La_2Ti_2O_7陶瓷的电学性能的影响,并对导电机理做了初步的探讨分析.实验表明,随着Sr量的增加,电导激活能有下降的趋势,导致材料的电导率增加.在100 Hz～10 MHz频率下未掺杂Sr和掺杂量为x=0.01试样的介电常数分别为46和67,介电损耗都在1×10~(-3)数量级,说明这种材料具有较好的介电性能.     

正交Li1-xMnO2(0≤x≤0.95)首次充电过程中物相及结构的演变

用高精度非原位XRD结合Rietveld精修对正交Li1-xMnO2(简写为o-Li1-xMnO2,0≤x≤0.95)在首次充电(电化学脱锂)过程中物相及结构的演变进行了研究。结果表明,o-LiMnO2电极的电压升高速率与其结构的变化有关;随着电化学脱锂o-LiMnO2发生一系列相变。证实了文献的理论计算和由晶体学推测出的相变过程,即相变产物中先后出现岩盐型锰酸锂和类尖晶石型锰酸锂。相变结束后,产物中只有岩盐型和类尖晶石锰酸锂2种物相。随着充电的进行,都有Li+从岩盐型和类尖晶石锰酸锂晶格中脱出,二者晶胞参数逐渐变小,微结构也不断变化。     

La_((1+x)/3)Ba_((2-x)/3)Mn_xCu_(1-x)O_3(0.8≤x≤1)晶体结构和输运性质

用固态反应法制备了名义组分为 L a(1 + x) /3Ba(2 - x) /3Mnx Cu1 - x O3(0 .8≤ x≤ 1) 的系列试样。试样结构的单相性经粉末 X射线衍射分析而得以证实 ,且随 Cu的掺杂其结构由未掺杂时的立方对称性转变为正交对称性。输运实验表明 :所有试样均经历了半导体到金属的转变 ,但转变温度 TP随掺杂量增加而逐渐移向低温端 ;外加磁场大大增加了 TP附近的导电性 ,导致 TP附近最大磁电阻效应的出现     

Ce1-xNdxO2-x/2(0≤x≤0.6)纳米粉体的低温燃烧合成

采用低温燃烧合成法,在柠檬酸-硝酸盐体系中合成了Ce1-xNdxO2-x／2（0≤x≤0.6）固溶体纳米粉体．X射线衍射（XRD）结果表明,Nd^3＋取代Ce^4＋形成具有单相立方萤石结构的固溶体,其晶格常数随Nd^3＋掺杂浓度的增大而线性增加,晶粒尺寸在15-24am之间．透射电镜（TEM）结果表明,粉体颗粒尺寸在2m-40am之间,分散性较好,具有较高的烧结活性．Raman光谱结果表明,F2g宽化峰的出现与掺杂后固溶体中产生的氧空位有关,并且随着掺杂浓度的增加,氧空位数量也随之增加．X射线荧光光谱（XRF）的分析表明,实际掺杂浓度非常接近原始化学计量比．     

Bi掺杂对Ba_(6-3x)La_(8+2x)(Ti_(0.95)Zr_(0.05))_(18)O_(54)(x=2/3)陶瓷的烧结性能和介电性能的影响

采用传统固相反应法制备Ba6-3x(La1-mBim)8+2x(Ti0.95Zr0.05)18O54(x=2/3)微波介质陶瓷,研究Bi掺杂对Ba6-3xLa8+2x(Ti0.95Zr0.05)18O54(x=2/3)陶瓷的烧结性能、微观结构以及介电性能的影响。结果表明:当0m0.4时,Bi3+取代A1位的La3+生成单相类钨青铜型固溶体;当Bi3+的掺杂量超过这个范围时,La0.176Bi0.824O1.5作为第二相出现在固溶体中;Bi3+的掺入使Ba6-3xLa8+2x(Ti0.95Zr0.05)18O54(x=2/3)陶瓷的烧结温度从1400℃降低到1300℃,同时,其介电常数大幅度提高,谐振频率温度系数减小,但品质因数急剧减小;当m=0.05时,1350℃下保温2h烧结获得的陶瓷具有微波介电性能,εr=88.63,Q·f=4395GHz,τf=6.25×10-6/℃。     

热处理对锂铁磷酸盐玻璃电性能的影响

采用熔体淬冷方法制得锂铁磷酸盐玻璃粉体，粉体经干压成型后进行热处理，并进而测定了热处理样品的电性能。分析表明，热处理条件对该玻璃体系电性能的影响是通过对其结构的改变来实现的，主要表现在玻璃体软化和形成晶相两个方面，不同的热处理温度和热处理保温时间对载流子运动的影响不同。     

Electrical conductivity of Na3AlF6-AlF3-Al2O3-CaF2-LiF（NaCl） system electrolyte

A PGSTAT 30 and a BOOSTER 20A were used to measure cell impedance.Electrical conductivity was gained by the Continuously Varying Cell Constant Technique.Electrical conductivity of KCl was measured for comparison.The results prove that the method is reliable and accurate.The electrical conductivity of Na3AlF6-AlF3-Al2O3-CaF2-LiF(NaCl)system was studied by this method.Activation energy of conductance was obtained based on the experiment results.The experiments show that electrical conductivity is increased greatly with NaCl and LiF added.Increasing 1%LiF(mass fraction)results in corresponding increase of 0.0276 S/cm for superheat condition of 15℃.For NaCl,it is 0.024 S/cm.Electrical conductivity is increased by 0.003 S/cm with 1℃temperature increase.The electrical conductivity is lower than that predicted by the WANG Model and higher than that predicted by the Choudhary Model.     

Microstructure and electrical properties of Lu2O3-doped ZnO-Bi2O3-based varistor ceramics

Lu2O3-doped ZnO-Bi2O3-based varistor ceramics samples were prepared by a conventional mixed oxide route and sintered at temperatures in the range of 900-1 000°C,and the microstructures of the varistor ceramics samples were characterized by X-ray diffractometry(XRD)and scanning electron microscopy(SEM);at the same time,the electrical properties and V-I characteristics of the varistor ceramics samples were investigated by a DC parameter instrument for varistors.The results show that the ZnO-Bi2O3-based varistor ceramics with 0.3%Lu2O3(molar fraction)sintered at 950°C exhibit comparatively ideal comprehensive electrical properties.The XRD analysis of the samples shows the presence of ZnO,Bi-rich,spinel Zn7Sb2O12 and Lu2O3-based phases.     

一种含氟化镁电解质体系的温度、密度和导电度论证

本文对一种在生产中使用的含镁铝电解质体系的温度、密度、导电度利用经验公式进行了论证。通过论证得出如能通过技术手段和管理手段对电解质中各成份含量进行精细控制，电解生产可以在较低温度下高效运行；该电解质体系和铝液的密度差在一些情况下较小，生产中注意提前调控；该电解质体系和低分子比高氟化钙电解质体系的导电度相当。     

热处理对Li2O-P2O5玻璃电性能的影响

采用熔体淬冷方法制得锂磷酸盐玻璃粉体，粉体经干压成型后进行热处理，并进而测定了热处理样品的电性能。结果表明，在高于和低于玻璃转变温度（Tg）的温度下进行热处理时，样品的电导活化表现出了不同的变化趋势，但随着热处理时间的延长都逐渐趋于一个恒定值。     

添加剂对钛酸铝陶瓷性能的影响(英文)

研究了添加剂对钛酸铝陶瓷的体积密度、物相组成、机械强度以及抗热震性的影响。用反应烧结法制备钛酸铝陶瓷,其中添加剂为MgO、SiO2、Fe2O3及其复合添加剂。通过阿基米德排水法测试陶瓷的体积密度及气孔率,采用三点弯曲方法测试陶瓷强度,并利用热循环实验测定陶瓷抗热震性。结果表明:MgO、SiO2、Fe2O3及其复合添加剂有利于减少气孔率,提高钛酸铝陶瓷强度,增强陶瓷抗热震性。添加剂能促进烧结,形成新相,并且可以提高钛酸铝的晶格常数c。     

Effects of heat treatment on the properties of powder injection molded AIN ceramics

The effects of two different heat-treatment atmospheres,nitrogen atmosphere and reducing nitrogen atmosphere with carbon,on the properties of Y2O3-doped aluminum nitride (AlN) ceramics were investigated.The AlN powder as a raw material was synthesized by self-propagating high-temperature synthesis (SHS) and compacts were fabricated by employing powder injection molding technique.The polymer-wax binder consisted of 60 wt.% paraffin wax (PW),35 wt.% polypropylene (PP),and 5 wt.% stearic acid (SA).After the removal of binder,specimens were sintered at 1850℃ in nitrogen atmosphere under atmospheric pressure.To improve the thermal conductivity,sintered samples were reheated.The result reveals that the heat-treatment atmosphere has significant effect on the properties and secondary phase of AlN ceramics.The thermal conductivity and density of AlN ceramics reheated in nitrogen gas are 180 W·m-1 K-1 and 3.28 g,cm-3 and the secondary phase is yttrium aluminate.For the sample reheated in reducing nitrogen atmosphere with carbon,the thermal conductivity and density are 173 W.m-1.K-1 and 3.23 g·cm-3,respectively,and the secondary phase is YN.     

Effects of heat treatment on the properties of powder injection molded AlN ceramics

The effects of two different heat-treatment atmospheres,nitrogen atmosphere and reducing nitrogen atmosphere with carbon,on the properties of Y2O3-doped aluminum nitride (AlN) ceramics were investigated.The AlN powder as a raw material was synthesized by self-propagating high-temperature synthesis (SHS) and compacts were fabricated by employing powder injection molding technique.The polymer-wax binder consisted of 60 wt.% paraffin wax (PW),35 wt.% polypropylene (PP),and 5 wt.% stearic acid (SA).After the removal of binder,specimens were sintered at 1850℃ in nitrogen atmosphere under atmospheric pressure.To improve the thermal conductivity,sintered samples were reheated.The result reveals that the heat-treatment atmosphere has significant effect on the properties and secondary phase of AlN ceramics.The thermal conductivity and density of AlN ceramics reheated in nitrogen gas are 180 W·m-1 K-1 and 3.28 g,cm-3 and the secondary phase is yttrium aluminate.For the sample reheated in reducing nitrogen atmosphere with carbon,the thermal conductivity and density are 173 W.m-1.K-1 and 3.23 g·cm-3,respectively,and the secondary phase is YN.