Chemical Bond and Spectral Effect of Rare Earth Compound Crystals

The chemical bond parameters and ionic polarizabilities in complex crystals are calculated.Themechanism of host influence on the nephelauxetic effect and hypersensitive transition is discussed.     

Syntheses and Crystal Structure Characterizations of New Rare Earth Copper Bismuth Compounds RE CuBi2 （RE = La, Gd and Dy）

The tide new compounds with chemical formula RE CuBi2 were synthesized by arc melting method followed by annealing. The crystal structures refined using Rietveld method and X-ray powder diffraction data show to be isotypic to CaMnBi2 structure type with space group P4/nmm (No. 129). The unit cell parameters are a=0.457946(4)nm,c =0. 98858(2) nm, V =0. 207319(8) nm^3 for LaCuBi2, a = 0.449279(9) nm, c = 0. 95958(4) nm, V = 0. 19369(2) nm^3 for GdCuBi2 and a =0. 447680(7) nm, c =0. 95124( 3 ) nm, V = 0. 190644(5 )nm^3 for DyCuBi2 respectively, showing lanthanide contraction. The structure is characterized by layers of edge-shearing CuBi4 tetrahedron and covalently bonded Bi square net separated by rare earth atoms.     

Spectra of Solid Rare Earth Complexes RE（C5H8NS2）3（C12H8N2）

The solid complexes RE (C5H8NS2)3(C12H8N2) (RE=La,Pr,Nd,Sm-Lu) were synthesized in absolute ethanol, and were characterized by IR,UV and FS spectra. IR results reveal that the RE^3 coordinated with sulfur atoms of APDC and nitrogen atoms of o-phen. As for UV spectrum of the complexes, energy transfer between o-phen and RE^3 is the primary process, and the main absorption peaks show a slight red shift than that of o-phen; FS spectrum, as a comparison, the complexes Sm (C5H8NS2)3(C12H8N2) and Eu (C5H8NS2)3(C12H8N2) have stronger fluorescence character.     

Synthesis and Characterization of Complexes of Rare Earth Nitrates with N, N -Bis（3-pyridylmethyl） -1,2-ethylenediamine

In this paper, a series of complexes of rare earth nitrates with N, N‘-bis(3-pyridylmethyl)-1,2-ethylenediamine ligand (L) were synthesized from the acetonitrile solution. The obtained new complexes were characterized by elemental analysis, IR spectroscopy and thermogravimetric analysis. The results showthat all the complexes have l: 1 molar ratio of metal,     

Bibliography of Science and Technology of Rare Earth Published in China （1992）

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Effect of Rare Earth （Niobium） on Costed and Hot-Rolled Microstructure and Properties of Heavy Rail Steels

Effect of Rare Earth (Niobium) on Costed and Hot-Rolled Microstructure and Properties of Heavy Rail Steels     

Synthesis, Characterization and Luminescence Properties of Rare Earth Complexes with Bis （Pyridinyl-Amide）

A ligand, N^1, N^4-di （ pyridin-2-yl ） succi- namide （L） and its lanthanide（ IH ） complexes （RE = La, Eu, Tb, Gd, Yb ） were synthesized and characterized in detail. The results indicate that the composition of the binary complexes is determined as [ REL （H2O）2（NO3）2] NO3, that the complexes are 1 ： 1 electrolytes in DMF, and that the Tb^3＋ complex has brightly green fluorescence in a solid state. At the same time, the energy levels of the excited triplet states for the six ligands were determined to be 22989 -1 cm . The fact that the ligand sensitize Tb^3＋ complexes was explained by the relative energy gap between the lowest triplet energy level of the ligand （T） and ^5Dj of Tb^3＋ or Eu^3＋ . When 2000 cm^-1 〈 △E（T-^5D4） 〈 3000 cm^-1, the luminescent intensity of the Tb^3＋ complex is stronger. When 3000 cm^-1〈 △E （T-^5D1）, the luminescent intensity of the Eu^3＋ complex is weak- er or close to nil. This means that the triplet energy level of the ligand is a chief factor that dominates RE^3＋ luminescence.     

Study on Rare Earth Electrolyte of Ce0.9 RE0.102－δ （RE=Pr, Nd, Sm,Gd, Dy）

The solid solutions Ce0.9RE0.102-δ(RE=Pr,Nd,Sm,Gd,Dy) were prepared by sol-gel method, The XRD measurement shows that the solid solution is crystallized in cubic fluorite-type structure and the cell volume of Ce0.9RE0.1O2-δ decreases with the increase of atomic number of RE. The ionic conduction for Ce0.9RE0.1O2-δ was measured by impedance spectroscopy and Ce0.9Pr0.1O2-δ has better conductivity. The linear thermal expansion of Ce0.9RE0.1O2-δ decreases with the increase of atomic number of RE.     

Stability of Rare Earth Ion-N, N′-bis（2′-Pyridine）methyl-1,10-Phenanthroline-2,9-Dimethanmine Binary Complexes

1 ,10 Phenanthrolinehasbeenextensivelyusedasanazaheterocyclicchelateligandinbothanalyticalandpreparativecoordinationchemistry[1] .Asanim portantligand ,1,10 phenanthrolineunitplaysanim portantroleforthedevelopmentofthesupramolecularchemistry .Manynovelsupramolecularcompoundsin clude 1,10 phenanthrolineunit[2～ 4 ] .Furthermore ,consideringtheuniquecombinationofchemicalstabil ities ,redoxproperties ,luminescenceemissionandex citedstatelifetime ,derivativesof 1,10 phenanthrolinehaveplayedama…     

Syntheses, Characterization and Antitumour Activities of Rare Earth Metal Complexes with 2- （ （ （4,6-dimethyl）-2-Pyrimidinyl ）thio ）-Acetic Acid

Pyrimidineringsystemswhichcontainmercapto grouphaveverycloserelationshiptosulphuranalogues oftheDNAbases.Mostofthosecompoundswerere portedtobetumorinhibitors,antimycotic,antileuke mic,tuberculoatat,antithyroid,andhypoglycaemic agentsandhaveattractedinterestofmany chemists[1～6].Nigametal[6]synthesizedcorresponding4,6dimethyl5(arylazo N substitutedp sulphamyl benzeneazo)pyrimidin2thiolsbycondensationof4,6dimethylpyrimidinyl2thiolwithdifferentdiazotised bases,invitroalltheobtainedthiolcompounds…     

稀土在09CuPTi（RE）钢中的作用机理

为研究稀土在09CuPTi(RE)钢中的作用机理,首先需要研究稀土分别与铜、磷、钛的相互作用。本文用固体电解质电池定氧、低温无水电解及等离子发射光谱等测试手段,研究了Fe—Cu—Ce,Fe—P—Ce,Fe—Ti—Ce,溶液体系在1600℃平衡时溶质元素的相互作用规律。得到1600℃铁液中铈分别与铜、磷、钛相互作用系数e_(ce)~p、e_(ce)~(Ti);观察到铈不与铜、磷、钛生成金属间化合物,而与微量氧、硫生成Ce_2O_2S型化合物;得到1000℃时反应Ce_2O_2S=2[O]+2[Ce]+[S]的平衡常数K。用金相和岩相显微镜、扫描电镜、电子探针及X射线衍射等方法研究了稀土对09CuPTi(RE)钢的脱氧、脱硫作用、对夹杂物球化变性作用、提高力学性能的机理、以及稀土在该钢中的固溶量,并通过室内加速腐蚀试验研究了09CuPTi(RE)钢的耐大气腐蚀机理,得到了稀土在09CuPTi(RE)钢中的作用机理。     

Electrical conductivity of REF_3-LiF(RE=La and Nd) molten salts

The electrical conductivity of REF3-LiF(RE=La and Nd) molten salts(xREF_3=5 mol%-40 mol%) was systematically measured over the temperature range from 1223 to 1423 K by using continuously varying cell constant(CVCC) method.Electrical conductivity values of LaF3-LiF and NdF_3-LiF molten salts within the studied ranges are 4.11-9.39 and 3.62-9.51 S/cm,respectively.The composition and temperature dependences of electrical conductivity and the factor of RE_2 O_3 on electrical conductivity were investigated.The electrical conductivity nonlinearly decreases with the increasing mole percent of REF_3 for the changing of structural ion in molten salts.A good linear relationship between the natural logarithm of electrical conductivity(lnκ) and the reciprocal of the absolute temperature(T~(-1)) can be interpreted by the trend that electrical conductivity linearly increases with increasing temperature.Although it is an important factor of RE_2 O_3 on electrical conductivity,the influence of RE_2 O_3 on conductivity is small for the very limited solubility of RE_2 O_3 in REF_3-LiF molten salts.The results of this work supplement the present electrical conductivity data of rare earth fluoride electrolyte.     

RE2FeSb2(RE=Y,Dy,Er)充电过程研究

制备了化学计量比为RE2FeSb2(RE=Y,Dy,Er)的稀土化合物并测试了合金的电化学性能.研究发现RE2FeSb2(RE=Y,Dy,Er)合金电极充放电过程中呈现2个充放电平台.合金电极在KOH溶液中浸润24h后极化程度不同;Y2FeSb2在浸润后极化程度比Dy2FeSb2和Er2FeSb2更深,使得前者首次充电过程明显区别于后2种合金电极.充放电循达到五十次以后,合金电池低电位充电平台逐渐消失,高电位充电平台的充电容量缓慢减小,合金电池循环充放电能力下降.     

Synthesis and Characterizations of Rare Earth Compounds RE(HCO 2) 3(HNO 2)(H 2CO 2)(RE=Y, Tb, Dy, Ho, Er, Yb, Tm)

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Calculation of RECl_3-CaCl_2-LiCl Phase Diagrams(RE=La, Ce, Pr, Nd)

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Studies on NaLn(WO_4)_2 Single Crystals(Ln=La,Pr,Nd)

The crystals of NaLn(WO4)_2(Ln=La,Pr,Nd)are grown from a melt of LiCl-Na_2WO_4 flux by slowcooling method.The chemical analysis data show that the crystals are NaLa(WO_4)_2,NaPr(WO4)_2 andNaNd(WO_4)_2 respectively.The structures of the crystals are ascertained that they belong to scheelite structureof the tetragonal system with a space group of 14_1/a.The lattice parameters of the crystals have beencalculated.It is found that the cell volume of NaLn(WO_4)_2 crystals decrease with a decrease of Ln~(3 )radius.The bond distances and their angles in NaLa(WO_4)_2 and NaNd(WO_4)_2 are given.It is found that inaccordance with the decrease of ionic radii of Ln~(3 )due to increase of atomic number,the bond distances betweenLn-O,Ln-Ln and W-O decrease regularly.The infrared spectra of NaLn(WO_4)_2 are measured.Thetetrahedra characteristic absorptions of WO_4~(2-)are shown.The sensitization of host lattice is observed from theexcitation and fluorescent spectra of NaLa(WO_4)_2 and NaPr(WO_4)_2.     

轻稀土镧取代M型钡铁氧体超微粉末的合成与表征

利用溶胶-凝胶自蔓延高温合成法制备了稀土镧掺杂钡铁氧体BaLaxFe12-xO19超微粉末。讨论了起始溶液pH值、柠檬酸配比、煅烧温度等对粉末性能参数的影响。用X射线衍射仪、扫描电子显微镜和振动样品磁强计等对粉末的结构、形貌和磁学性能进行了研究。     

Quantum Chemical Calculation on the Structures and Electronic Properties of Phosphonate Ester as Rare Earth Extractants

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Synthesis, Structure and Bonding Feature of New Metallic Zintl Phases RE 3Cu 3Sb 4(RE=Nd, Sm, Tb, Dy, Ho)

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