材料期刊网

STUDIES ON FERROM AGNETIC COUPLING COMPLEXES OF LANTHANIDES WITH NITRONYL NITROXIDES

Z.Wang1) , Q.H.Zhao2) , D.Z.Liao2) , Z.H.Jiang1) , S.P.Yana and G.L.Wang1) 1) Department of Chemistry , Nankai University , Tianjin 300071 , China. 2) State Key Laboratory Coordination Chemistry , Nanjing University , Nanjing 210008 , China

金属学报(英文版)

Five novelcomplexesofformula 〔Ln( pfpr)3〕2 NITRS·nH2 O, where Ln = Nd, Sm , Eu, Gd, Dy; pfpr= pentafluoropropionate; NITRS= 2 - (2’- thienyl) - 4,4 ,5 ,5 te tramethylimidazoline 1 oxyl 3 oxide, and n= 6(for Nd);4(for Eu and Gd) ;2(for Sm and Dy), have been synthesized. Thesecomplexes werecharacterized by elemental analysis, IR, electronicspectra and EPR. Thevariabletemperature(2 300 K) magneticsusceptibility ofthecomplex 〔Gd(pfpr)3〕2 NITRS·4 H2 Owas determined and discussed. Theexchange integral,J= 0 44 cm 1 , wasfoundtobepositive,indicating a weakferromagneticspin ex changeinteraction between theradicaland Gd(III) ion.

关键词: ferromagnetism , null , null , null

BST掺杂对M/Z型六角铁氧体复磁导率(1MHz～1GHz)的影响

陈耿 , 谢建良 , 黄鹏

功能材料

采用陶瓷工艺制备C02Z(Ba3(Co0.4Zn0.6)2Fe23.4O41)和BaM(BaFi1.4Co1.4Fe9.2O19)六角铁氧体,二次球磨时掺杂少量BST(BaSrTiO3)铁电材料,对比研究了BST掺杂对Z型和M型铁氧体在1MHz～1GHz频率范围内相对复磁导率(μr=μr1-iμr")的影响.BST的掺杂使Z型铁氧体μr增大,共振频率点移向低频;使M型铁氧体的μr减小,共振频率点移向高频.通过对其微观结构和磁参数的测试分析,讨论了BST掺杂对Z型和M型铁氧体复磁导率不同影响的作用机理.

关键词: Z型六角铁氧体 , M型六角铁氧体 , 磁晶各向异性场 , 相对复磁导率

Two-step magnetization in a spin-chain system on the triangular lattice: Wang-Landau simulation

Physical Review B

The Wang-Landau algorithm is used to study the thermodynamic and magnetic properties of triangular spin-chain system based on two-dimensional Ising model in order to understand the magnetic-order dynamics in Ca(3)Co(2)O(6) compound. The calculated results demonstrate that the equilibrium state of the rigid spins produces the two-step magnetization curve at low temperature even when the random-exchange term is considered. This work indicates that the four-step magnetization behavior observed experimentally must be due to the nonequilibrium magnetization.

关键词: calcium compounds;exchange interactions (electron);Ising model;magnetisation;thermodynamics;one-dimensional ca3co2o6;density-of-states;compound ca3co2o6;phase-diagram;proteins;crystal

SOFC阴极材料(La_(0.85)Sr_(0.15))_y(Mn_(1-z)Cr_z)O_3的物理性能和化学稳定性

杨威 , 隋智通

材料研究学报

采用烧结法制备阴极材料(La0.85Sr0.15)y(Mn1z-Crz)O3(y=0.85;1;z=0.1,0.2).研究了多孔锰酸镧与致密ZrO2(8mol%Y2O3)界面的成分变化和显微形貌(La0.85Sr0.15)(Mn0.9Cr0.1)O3呈现高电子电导率、良好的热膨胀系数匹配和化学稳定性而(La0.85Sr0.15)MnO3未起到阻止界面退化的作用在1300～1500℃范围内Mn、La、Zr和Sr发生扩散,其中Mn的扩散明显

关键词: SOFC , lathanum manganite. chemical stability , thermal expansion , conductivity , null

Subsolidus phase relation and crystal structure in the Pr(1+x-y)Ba(2-x-z)Ca(y+z)Cu(3)O(7 +/-delta) system

Applied Physics a-Materials Science & Processing

The Pr(1+x)Ba(2-x)Cu(3)O(7+/-delta) solid solution was investigated by means of X-ray powder diffraction combined with Rietveld analysis. A Pr123 single phase could be synthesized under Pr-rich conditions by sintering at 950 degreesC in air. The solubility range of Pr(1+x)Ba(2-x)Cu(3)O(7+/-delta) solid solution is 0.08 less than or equal to x less than or equal to 0.80. The structure of Pr(1+x)Ba(2-x)Cu(3)O(7+/-delta) for 0.08 less than or equal to x less than or equal to 0.30 is orthorhombic. The structure transforms into tetragonal for 0.30 less than or equal to x less than or equal to 0.80. To form the Pr123 single phase, the Ba sites in the Pr123 structure must have partial Pr ions, and the least amount is x = 0.08. Ba ions cannot occupy the sites of Pr ions. In the Pr123 structure, Ca ions can replace Pr ions; the highest value is x = 0.4 in the PrBa(2-x)Ca(x)Cu(3)O(7+/-delta) system under our experimental conditions. However, Ca ions cannot replace B a ions. The ionic radius plays a more important role than the chemical properties in the substitution between Pr, Ba and Ca ions in the Pr123 structure.

关键词: cu-o system;approximately 950-degrees-c;superconductivity;diagram;pr;growth;nd;prba2cu3o7-delta;praseodymium;property

正极材料zLi2MnO3·（1-z）LiNi0.4Mn0.4Co0.2O2的合成与性能

钟耀东 , 李志同 , 郭远刚 , 周权 , 周凤瑞 , 强颖怀 , 杨凌玲 , 霍瑛 , 赵思茜

材料科学与工程学报

富锂锰过渡金属层状正极材料以其成本低、安全、容量高受到广泛关注,X射线衍射（XRD）和电化学性能测试显示以共沉淀结合煅烧成功合成富锂层状正极材料zLi2MnO3.（1-z）LiMn0.4Ni0.4Co0.2O2（z=0.2,0.4,0.6）。其中z=0.4组分的放电容量达到210mAh/g（2-4.8V,0.05C）,远高于z=0.6组分,而经20个充放电循环的稳定性也优于z=0.2组分。微分容量分析表明z=0.2组分中因Ni/（Co＋Mn）比值较大和Li2MnO3含量较少可能导致其容量逐渐衰减。z=0.6则因所含LiMn0.4Ni0.4Co0.2O2量较少,造成其放电容量较低;z=0.4拥有最佳Li2MnO3及LiMn0.4Ni0.4Co0.2O2组合使其容量和循环性能最好。

关键词: zLi2MnO3·(1-z)LiMn0.4Ni0.4Co0.2O2 , 正极材料 , 循环性能 , 容量

(Z)-2-(1H-咪唑-1-基)-1-(2,3,4-三甲氧基)苯乙酮肟酯的设计与合成

杨松 , 宋宝安 , 李正名 , 廖仁安 , 刘刚

应用化学 doi:10.3969/j.issn.1000-0518.2002.03.013

合成了8个(Z)-2-(1H-咪唑-1-基)-1-(2,3,4-三甲氧基)苯乙酮肟脂(Ⅳ)新化合物,收率在62.1%～84.1%之间. 经元素分析、红外光谱、核磁共振氢谱表征了它们的结构,并讨论了化合物构型与光谱特征之间的关系.

关键词: 三甲氧基苯乙酮肟 , 酯 , 咪唑 , 合成 , 立体异构体

Z型铁氧体Ba_3（MnZn）_xCo_（2（1-x））Fe_（24）O_（41）的微波吸收性能

周克省 , 陈颖 , 秦宪明 , 邓联文 , 夏辉 , 黄生祥 , 卢玉娥 , 齐伟 , 韩建华

功能材料

用溶胶-凝胶法制备锰锌掺杂Z型钡钴铁氧体Ba3（MnZn）xCo2（1-x）Fe24O41（x=0.0、0.1、0.2、0.3、0.4、0.5）样品。用XRD和SEM对样品的晶体结构、颗粒形貌进行表征,用微波矢量网络分析仪测试该样品在2～18GHz微波频率范围的复介电常数、复磁导率,根据测量数据计算电磁损耗角正切及反射率,探讨该材料的微波吸收性能与电磁损耗机理。结果表明样品为Z型六角铁氧体晶体结构,颗粒呈六角片状形貌;当样品厚度为2.2mm、x=0.4时,在频率3.9GHz处吸收峰值为38.5dB,10dB以上频带宽度为3.8GHz;该材料能在1～5.8GHz微波低频范围实现有效吸收,其微波吸收兼具磁损耗和介电损耗,但磁损耗更为显著。

关键词: 溶胶-凝胶法 , Z型钡铁氧体 , 微波吸收 , 电磁损耗

E-、Z-2＇-(1-咪唑基)-O-(α-甲基-二氯苄基)-2,4-二氯苯乙酮肟硝酸盐的合成与抑菌活性

李再峰 , 罗富英

应用化学 doi:10.3969/j.issn.1000-0518.2001.06.014

以间二氯苯、氯乙酰氯和咪唑为原料,利用成肟和引入咪唑基顺序不同,首先合成了E-,Z-2＇(1-咪唑基)-2,4-二氯苯乙酮肟(IE、I2),从二氯苯合成了α-氯-二氯取代乙苯(ⅡA、ⅡB和Ⅱc),咪唑基-二氯苯乙酮肟顺反异构体(Ⅱz、ⅡE)分别与α-氯-二氯乙苯反应,生成E-、Z-2＇-(1-咪唑基)-O-(α-甲基-二氯苄基)-2,4-二氯苯乙酮肟硝酸盐共6种新化合物,产率为57.5%～64.5%,新化合物结构经元素分析IR和1HNMR表征.初步实验表明,各化合物对水稻苗腐根有不同程度抑制活性.

关键词: E-、Z-(咪唑基)-O-(α-甲基-二氯苄基)-二氯苯乙酮肟硝酸盐,咪唑基-二氯苯乙酮肟,α-氯-二氯乙苯,合成,抑菌活性

Lax Cey Prz Nd1-xy-z Ni3.55 Co0.75 Mn0.4 Al0.3储氢合金中稀土元素配比规律的研究

武文权 , 李重河 , 钦佩

功能材料

应用均匀试验设计法设计LaxCeyPrzNd1-x-y-zNi3.55Co0.75Mn0.4Al0.3(0＜x,y,z＜1)储氢合金的成分,通过大量的、统一的实验,来研究不同稀土配比的合金与其容量、电压、循环稳定性等电化学性能之间的关系,重点应用模式识别的人工智能方法分析实验数据并建立了相关的模型,结果显示出很好的规律性.

关键词: 储氢合金 , 稀土元素 , 模式识别 , 均匀设计