Synthesis and Characteristic of a New Niobate:Ba_5NaCo_0.5Nb_9.5O_30

A new niobate crystal was synthesized for the first time in BaO-Na2O-Co2O3 -Nb2O5 system by solid state reaction and the flux method. The new compound was studied by X-ray diffraction, electron probe. N-ray microanalysis, chemical analysis and SEM. The result of the X-ray diffraction shows that Ba5 NaCo0.5 Nb9.5 OK) belongs to tetragonal tungsten bronze structure with space group P4bm( 100) and lattice parameters a = b = 12.4453(2) A, c = 3. 9770 (3) A and Z = 1. The structure of the compound is different from that of Ba4Na2Nb10O30     

Preparation, Characterization and Dielectric Properties of Ba_6Mg_(0.67)Nb_(9.33)O_(30) Ceramic

1IntroductionSince the discovery of ferroelectricity andrelated prop-ertiesin BaTiO3,alarge amount of research workonoxides,insearch of novel materials for industrial applications,hasbeen done.High performance dielectric ceramics is appliedas key material…     

Synthesis and Dielectric Properties of Ba_3NaBiNb_(10)O_(30) Ceramics

1　ＩｎｔｒｏｄｕｃｔｉｏｎＦｅｒｒｏｅｌｅｃｔｒｉｃｓｗｉｔｈｔｈｅｔｕｎｇｓｔｅｎｂｒｏｎｚｅｔｙｐｅｓｔｒｕｃｔｕｒｅｈａｖｅｅｘｃｅｌｌｅｎｔｆｅｒｒｏｅｌｅｃｔｒｉｃ ,ｐｉｅｚｏｅｌｅｃｔｒｉｃ ,ｐｙｒｏｅｌｅｃｔｒｉｃ ,ｅｌｅｃｔｒｏ ｏｐｔｉｃ ,ａｎｄｎｏｎｌｉｎｅａｒｏｐｔｉｃａｌｐｒｏｐｅｒｔｉｅｓ[1,2 ] .Ｔｕｎｇ ｓｔｅｎｂｒｏｎｚｅｓｔｒｕｃｔｕｒｅｃｏｎｓｉｓｔｓｏｆａｎａｓｓｅｍｂｌａｇｅｏｆｃｏｒｎｅｒ ｓｈａｒｅｄ [ＭＯ6 ]ｏｃｔａｈｅｄｒａｌ (Ｍ =Ｔｉ,Ｎｂ ,Ｔａ ,ｏｒ…     

新铌酸盐A5LaSn3Nb7O30(A=Ba,Sr)的结构与介电特性

通过固相反应法,在AO-La2O3-SnO2-Nb2O5(A=Ba,Sr)体系合成了填满型钨青铜结构新铌酸盐Ba5LaSn3Nb7O30与Sr5LaSn3Nb7O30。采用X射线衍射分析和扫描电镜进行了结构分析,并测试了其介电性能。结果表明:Ba5LaSn3Nb7O30与Sr5LaSn3Nb7O30室温时均为四方钨青铜结构顺电相,其陶瓷体都具有高的介电常数、低的介电损耗与较小的介电常数温度系数。频率为1 MHz时,Ba5LaSn3Nb7O30陶瓷体的室温相对介电常数为171,介电损耗约为1.2×10-3;Sr5LaSn3Nb7O30陶瓷体的室温相对介电常数为164,介电损耗约为5.4×10-4。     

Synthesis and Characteristic of a New Niobate: Ba_5NaCr_(0.5)Nb_(9.5)_O_(30)

1　IntroductionTungsten bronze type (TTB)neonatematerialshavereceivedconsiderableattentionbecauseoftheirdielectricandferroelectricpropertiesandeaseofpreparation[1 5] .Thebronzecompositionscanberepresentedbythegeneralformulasas (A1 ) 4 (A2 ) 2 C4B1 0 O3 0…     

铌酸钡钠晶体的电光效应

本文从折射率椭球出发，分析了铌酸钡钠晶体在各种运用方式下的电光相位延迟，指出了其最佳运用方式，通过和目前常用的电光晶体比较，表明了其优越的电光性能和广泛的应用前景。     

Synthesis and Characterization of a New Triple-layered PerovskiteKSr_2Nb_3O_(10 )and Its Protonated Compounds

New layered perovskites, KSr2Nb3O10 and two new protonated niobates HSr2 Nb3O10·1.2H2O and HSr2Nb3O10,were synthesized by solid state reaction and ion-exchange reaction. These new compounds -were characterized by EPMA, AAS, XRD, IR, DTA and so on. The structure may be described as treble perovskite sheets [Sr2Nb3O10]- interleaved with K+ ,H3O + or H+. These new compounds are new members of the Dion-Jacob-sonseries with n=3 for the general formula M[An-1 NbnO3n+1], and their indexed X-ray powder diffraction data were first reported in the paper.     

新铌酸盐A5NdSn3Nb7O30的合成与介电特性

通过固相反应法在AO-Nd2O3-SnO2-Nb2O5(A=Ba,Sr)体系中合成了填满型钨青铜结构新铌酸盐A5NdSn3Nb7O30。分别采用X射线衍射分析和扫描电镜进行了结构分析,并进行了介电性能测试。结果表明,它们室温时都为四方钨青铜结构顺电相。A5NdSn3Nb7O30(A=Ba,Sr)陶瓷体具有高的室温相对介电常数,1 MHz时分别为182与144;低的介电损耗,分别为1.8×10-3和6.2×10-4;其介电常数温度系数(τε)分别为-1 071×10-6K-1和-507×10-6K-1。     

Synthesis and Characteristic of a New Niobate： BasNaCr0.5Nb9.5O30

A new niobate crystal was synthesized for the first time in BaO-NaO-Cr2O3-Nb2O3 system by the solid state reacition and the flux method. The new compound was studied by X-ray diffraction, electron probe, X-ray microanalysis, chemical analysis and SEM. The result of X-ray powder diffraction shows that Ba5NaCr0.5 Nb9.5O30 belongs to the tetragonal tungsten bronze structure, with space group P4 bin(100) and lattice parameters a=b=12. 4450 (2) A, c=3.9931 (2) A and Z=1. The X-ray powder diffraction lines of the compound were well indexed.     

Effects of LaNiO_3 Interlayer on the Microstructures and Electrical Properties of Ba_(0.9)Sr_(0.1)Ti_(0.99)Mn_(0.01)O_3 Multilayer

The aim of this work was to investigate the effects of low-resistivity interlayer on the physical properties of periodic Ba_(0.9)Sr_(0.1)Ti_(0.99)Mn_(0.01)O_3(BSTM) multilayers prepared by a chemical solution deposition method. A LaNiO_3(LNO) layer was inserted into the periodic BSTM multilayer artificially to form a sandwiched configuration of BSTM/LNO/BSTM. The capacitances at low frequencies(100 k Hz) of the sandwiched multilayer are significantly enhanced compared to that of the pure BSTM multilayer. The space charge accumulated at the LNO layer was proposed to explain the enhancement based on Maxwell-Wagner(M-W) model. However, LNO interlayer leads to an increase in the leakage current. A non-Ohmic conduction region is observed for BSTM/LNO/BSTM multilayer when the electric field exceeds 100 k V/cm. The results offer a new approach to achieve dielectric films with high dielectric constant.     

新化合物Sr_6CrNb_9O_(30)的合成及其结晶化学研究

在 Sr O- Nb2 O5- Cr2 O3 三元系统中 ,首次合成了新化合物 Sr6Cr Nb9O3 0 ,通过光学显微镜、化学分析、透射电镜、电子探针、X- ray衍射等手段对该化合物进行了研究 ,得到了晶体粉晶衍射数据 ,晶胞参数 a=b=1.75 0 8nm,c=0 .7748nm,晶体属正交晶系 ,空间群为 Cmm2 ,该化合物晶体具有钨青铜超结构     

Single-negative properties of Ba_2Co_（1.8）Cu_（0.2）Fe_（12）O_（22） and Ba_3Co_2Fe_（23.4）Zn_（0.6）O_（41） hexagonal ferrites

The electromagnetic properties of Ba2Co1.8Cu0.2Fe12O22 (Co2Y) and Ba3Co2Fe23.4Zn0.6O41 (Co2Z) were studied by measuring microwave scattering parameters.In the transmission spectra of Ba2Co1.8Cu0.2Fe12O22,a forbidden band emerges due to ferromagnetic resonance,and the permeability will turn to negative in the vicinity of the ferromagnetic resonance frequency.In the complex permittivity spectra of Ba3Co2Fe23.4Zn0.6O41,the negative permittivity can be obtained due to dielectric resonance.Therefore,Co2Y and Co2...     

SYNTHESIS AND X-RAY POWDER STUDY OF A NEW COMPOUND:Ba_6Ti_7Nb_9O_(42)

A new compound Ba6Ti7Nb9O42 was prepared for the first time by solid state reaction in BaO-TiO2-Nb2O5, ternary system. The X-ray powder diffraction data of the title compound was determined. Ba6Ti7Nb9O42 crystallizes in the hexagonal system -with unit cell parameters a=9.0527(4) A,c=11.790(1) A,and space group P63/mcm(193),z=1. The calculated and measured densities are 5. 293 g/cm3 and 5.285 g/cm3, respectively.     

二苯乙烯类荧光增白剂1,4-二(邻氰基苯乙烯基)苯的合成及晶体结构与光物理性质

以Witting-Homer反应合成了反式对称的1,4-二(邻氰基苯乙烯基)苯化合物,X-射线衍射分析测定了该化合物的晶体结构。测定了其在不同溶剂中的线性吸收光谱、荧光发射光谱及荧光量子产率。飞秒激光做光源研究了化合物的双光子光物理性能。测试(700～820 nm)结果表明:该化合物在蓝光波段有较强的荧光发射,化合物具有较高的荧光量子产率,在700 nm处有较大的双光子吸收截面(68 GM),具有双光子诱导蓝光发射光学特性。     

一个全新配体的合成及晶体结构研究

在甲醇溶液中 用ＮａＢＨ４还原１，４－二－１，４－二氧丁烷制备了一个全新的配体１，４－二－１，４－二氧丁烷，并得到配体的单晶晶体结构。     

合成铌铬酸钾晶体结构的电子衍射分析

本文利用透射电镜研究了掺铬铌酸钾晶体,采用电子衍射几何构图法测定了铌铬酸钾的晶体结构。它属六方晶系,晶胞参数为:a=9.14A,c=12.06A,为首次报道的人工新单晶。     

新铌酸盐化合物 Sr_2KNb_3O_(10) 晶体结构的透射电镜研究

在１４２０～１４８０℃高温合成了一种新的铌酸盐化合物Ｓｒ２ＫＮｂ３Ｏ１０晶体。用透射电子显微镜研究了该化合物的晶体结构,电子衍射几何构图法所得结果表明,该晶体属正交晶系,晶胞参数为：ａ＝０．７８４１ｎｍ,ｂ＝０．７８１２ｎｍ,ｃ＝２．９９１７ｎｍ,为首次报道的人工合成新晶体。     

一维链状化合物｛(C2H10N2)[Mo3O10]｝n的水热合成、晶体结构与表征

在水热条件下合成了一维链状结构多金属氧酸盐化合物{(C2H10N2)[Mo3O10]}n,并用IR、TG-DSC和单晶X-ray衍射等手段进行了表征。结果表明,化合物属于单斜晶系,P21/n空间群,晶胞参数a=0.808 40(2)nm,b=1.446 50(3)nm,c=0.891 50(2)nm,α=90°,β=98.140(2)°,γ=90°,V=1.031 97(4)nm3,Z=4,Dc=3.282g/cm3,R1=0.027 9,wR2=0.072 9。化合物分子结构单元由一个质子化乙二胺和一个[Mo3O210-]阴离子构成。[Mo3O210-]中相邻的MoO6八面体相互作用形成一维无限链状结构,毗邻的单链相互缠绕形成双链结构。热性质研究表明,标题化合物热稳定性较好,在290℃才开始有热失重的发生。同时,又将该化合物修饰到电极上,研究了其电化学行为。     

4,4''-(1-氢-1,2,4-三唑-1-亚甲基) 双苯甲腈的晶体结构

用四圆X-射线衍射研究了来曲唑的晶体结构,结果表明,来曲唑晶体属于单斜晶系,空间群为P21/n,晶胞参数a=7.030(14)(A), b=16.170(3)(A),c=13.360(3)(A),β=104.80°,V＝1 468.3(5)(A)3,Z＝4,晶格中分子间通过氢键和范德华力而形成二维网状超分子结构.     

含N杂环硫醚四核Cu（I）配合物的合成及晶体结构

采用溶液扩散法,利用含N杂环硫醚配体2-巯基-(2-甲基吡啶)-4-甲基嘧啶(L)和金属盐CuI反应合成了配合物[Cu₄I₄L₂],利用X线单晶衍射技术测定了其晶体结构,并对其进行了红外表征.结果表明,该配合物属单斜晶系,空间群为P2₁/n,晶胞参数:a=1.004 70(5) nm,b=0.893 04(4) nm,c=1.815 98(8) nm,β=99.847(10)°,V=1.605 36(13) nm³,Z=2,Mr=1 196.40.该配合物为四核结构,配合物分子间通过氢键、S…S和π-π等弱作用堆积成三维结构.