Influence of Lanthanum IonImplantation on Adhesive Property of Oxide Film Formed on Co40Cr Alloy

The isothermal and cyclic oxidizing kinetics of Co40Cr alloy and its lanthanum ionimplanted samples were studied at 1 000 ℃ in air by thermal gravimetric analysis (TGA). Scanning electron microscopy (SEM) was used to examine the Cr2O3 oxide film′s morphology after oxidation. Secondary ion mass spectrum (SIMS) method was used to examine the binding energy change of chromium caused by Ladoping and its influence on the formation of Cr2O3 film. Acoustic emission (AE) method was used in situ to monitor the cracking and spalling of oxide films during oxidizing and subsequent aircooling stages. Laser Raman spectrum was used to examine the stress changes within oxide films. A theoretical model was proposed relating to the film fracture process and was used to analyze the AE spectrum both on time domain and AEevent number domain. It was found that lanthanum implantation remarkably reduced the isothermal oxidizing rate of Co40Cr and improved the anticracking and antispalling properties of Cr2O3 oxide film. The reasons for the improvement were mainly that the implanted lanthanum reduced the grain size and internal stress of Cr2O3 oxide, increased the high temperature plasticity of oxide film, and remarkably reduced the number and size of Cr2O3/Co40Cr interfacial defects.     

Interaction of TbCl3 and lanthanide complexes with poly（N-vinylpyrrolidone）

The interaction of TbCl3 and lanthanide(III) β-diketonate complexes with poly(N-vinylpyrrolidone)(PVP) polymer was studied using fluorescence spectroscopy. In the presence of PVP the emission of Tb3+ in ethanolic solution of TbCl3 significantly increased owing to the excitation energy transfer from PVP to Tb3+ ions, which was more efficient as compared to a direct excitation of the Tb3+ 4f75d1 levels. In contrast, emission of NEt4Tb(hfa)4 and NEt4Eu(hfa)4 complexes was almost completely quenched in solution containing PVP. The PVP bound both Ln3+ ions and hfa ligands which caused decomposition of Ln-hfa complexes and switched off the excitation energy transfer from the ligand to the emitting Ln3+ ion. The important role of hydrogen bonds in stabilization of interaction of hfa ligands with PVP was indicated.     

Synthesis, Structure and Luminescent Properties of a Nine-Coordinated Praseodymium Complex

The Pr (TFA) 3phen ( C2H5OH ) quarternary complex with 2-thenoyhrifluoro-acetone ( TFA ), 1,10phenanthroline(phen) and ethanol were synthesized and characterized by single-crystal X-ray diffraction. The central Pr^3 ion is nine-coordinated. The infrared (IR)spectrum, diffuse reflectance (DR)spectrum and fluorescence measurements of the complex were investigated.     

Luminescent Properties of A Novel Terbium Complex Tb（o-BBA）3（phen）

A novel rare earth complex of terbium ion with 2-benzoylbenzoic acid and 1, 10-phenathroline （Tb（o-BBA）3 （phen）, o-BBA-2-benzoylbenzoic acid, phen = 1, 10-phenathroline） was used as an electroluminescent material for the first time. The Tb complex was blended with poly（N-vinylcarbazole） （PVK） in different weight ratios and spinn to coated into films （noted as PVK ：Tb films）. The photoluminescence （PL） properties of films were investigated and the optimum weight ratio between PVK and Tb（o-BBA）3（phen） was found to be 3：1. Monolayer devices with the structure ITO/PVK： Tb/AI were fabricated and emitted green light, which was characteristic of Tb^3＋ emission. The results show that mecha- nisms for PL and EL are different. The PL is considered to be caused because of energy transfer and direct excitation to the Tb（o-BBA）3（phen） molecule, while EL is mainly on charging trapping.     

Synthesis and Luminescent Properties of Ce^3＋ , Tb^3＋ Co-Doped ZH4B6O13

Green-photoluminescence material Zn4B6O13: Ce^3 , Tb^3 was first synthesized by spread method of high temperature and solid state reaction, which is cubic crystal system with lattice parameters : a0 =0. 7472 nm, V = 0.4172 nm^3, and structural properties are investigated by XRD. The excitation and emission band of Ce^3 ion singledoped in Zn4B6O13 transfer longer spectra 2.38 ～4.94 kk than in other matrices. Emission band of Ce^3 ion better overlaps with the ^7F6→^5G2,^5D1 ,^5H7 absorption band of Tb^3 . It shows that emission of Tb^3 ion is sensitized by Ce^3 . In Zn4B6O13:Ce^3 , Tb^3 , it is due to the energy transfer mechanism, resonance transfer of electric muhipolax interaction of the dipole-dipole between Ce^3 →Ce^3 and Ce^3 →Tb^3 . The color coordinates of ZB4B6O13: x =0.281, y =0.619. The mean diameter of the particles is 0.23μm.     

Synthesis and Structure of a Polymeric Complex [Ce（bphsb）2（NO3）3]n

Polymeric cerium nitrate complex with 1,4-bis (phenylsulfinyl) butane (bphsb) [Ce(bphsb)2(NO3)3]n (1) was synthesized and characterized. The crystal structure of the complex indicated that the ligand bphsb and cerium( Ⅲ ) ion form a polymeric double-bridge chain complex involving 18-membered macrometallocycles. Each cerium ion is coordinated by ten 0 atoms in a distorted 4,4-bicapped square antiprism. In the complex the disulfoxide ligand acts as bis-monodentate O-ligand bridging metal centers.     

Synthesis and thermal behavior of [Li(thf)_3(μ-Cl)La{N(SiMe_3)_2}_3] and its investigation as spin-coating precursor for lanthanum-based layer formation

The lanthanum(Ⅲ) complex [Li(thf)_3(μ-CI)La{N(SiMe_3)_2}_3](3) was obtained by the reaction of LaCl_3 with three equiv of Li[N(SiMe_3)_2]_3 in a tetrahydrofuran solution. The molecular structure of 3 in the solid state was characterized by a tetracoordinated anionic lanthanide(Ⅲ) amide in form of an adduct with LiCl(thf)_3 as evidenced by single crystal X-ray structure analysis. In order to study the suitability of 3 as a precursor for the deposition of La_2O_3/LiLaSiO4 by thin layer deposition techniques,its thermal behavior was investigated by thermogravimetry(TG) and TG-MS-coupled studies. TG studies show a two-step decomposition process, whereby volatile decomposition products can be detected during the second decomposition step. TG measurements under an atmosphere of oxygen produced La_2O_3, Calcination processes of 3 under ambient atmosphere for 10 h at 1000 ℃ gave La_2O_3 and LiLaSiO_4,which was confirmed by PXRD studies. Metal-organic 3 was applied as spin-coating precursor for La_2O_3 thin film formation giving the as-deposited layers nearly crack-free.     

Luminescence and Defect Properties of Novel Bluish-Green Phosphor β-Zn3（PO4）2： Zr^＋

Luminescence and defect properties of novel phosphor β-Zn3 (PO4) 2 : Zr^4 were systematically investigated. Corresponding to its lowest optical absorption transition at 240 nm, phosphor emits a bluish-green light at 485 nm, which yields the Stokes shift about 20000 cm^-1. The unusual optical properties of Zr^4 ion are ascribed to its uncommon coordination environment. In addition it shows intensive bluish-green long lasting phosphorescence (LLP) due to the existence of electron trap, which is generated by aliovalent substitution of Zr^4 ion for the cation site in the matrix as shown in thermoluminescence (TL) spectrum.     

Syntheses and Infrared Spectra of Rare Earth Complexes with Diethyl Phosphate

The title complexes Ln(DEP),(Ln=La,Sm,Eu,Ho and Yb)were synthesized by reaction of triethylphosphate with trivalent rare earth chlorides.The mechanism of thermo-decomposition of the complexes hasbeen studied.According to their IR spectra,the residues of the thermo-decomposition of the complexes wereidentified as Ln(PO_3)_3.Their IR spectra were measured and principal IR bands were assigned.The experimentalresults of the IR spectra of the complexes show that the title complexes have the same coordination form and mo-lecular configuration as rare earth,e.g.Sm,complex with dimethyl phosphate(Sm(DMP)_3).Each of the rareearth ion links three rare earth ions nearby through double“O-P-O”bridges to form a special network ofrings-linking-rings,each of which consists of twenty-four atoms.The Ln-O bond is principally ionic.     

Influence of Lanthanum Ion-Implantation on Adhesive Property of Oxide Film Formed on Co-40Cr Alloy

The isothermal and cyclic oxidizing kinetics of Co-40Cr alloy and its lanthanum ion-implanted samples were studied at 1 000 ℃ in air by thermal gravimetric analysis（TGA）.Scanning electron microscopy（SEM）was used to examine the Cr2O3 oxide film＇s morphology after oxidation.Secondary ion mass spectrum（SIMS）method was used to examine the binding energy change of chromium caused by La-doping and its influence on the formation of Cr2O3 film.Acoustic emission（AE）method was used in situ to monitor the cracking and spalling of oxide films during oxidizing and subsequent air-cooling stages.Laser Raman spectrum was used to examine the stress changes within oxide films.A theoretical model was proposed relating to the film fracture process and was used to analyze the AE spectrum both on time domain and AE-event number domain.It was found that lanthanum implantation remarkably reduced the isothermal oxidizing rate of Co-40Cr and improved the anti-cracking and anti-spalling properties of Cr2O3 oxide film.The reasons for the improvement were mainly that the implanted lanthanum reduced the grain size and internal stress of Cr2O3 oxide,increased the high temperature plasticity of oxide film,and remarkably reduced the number and size of Cr2O3/Co-40Cr interfacial defects.     

Synthesis and Characteristic of Poly（N-vinylacetamide） Containing Terbium Ion

Insulatinghostsdopedwithrareearthionsfinda widevarietyofapplication[1].Particularly,materials thathavefluorescentpropertiesarenotonlyattractive subjectsofresearch,butalsoimportantmaterialsfor manytechnologicaldevices.Rareearthdopedinor ganiccrystalsaresu…     

Emission of Rare Earth Complex Tb0.5Eu0.5 （asprin）3phen

The coprecipitate Tho.sEuo.5(asprin)3phen was synthesized. By doping the rare earth complex into polymer PVK, the EL device was fabricated with the structure of ITO/PVK: RE/PBD/AI. Compared with the device using PVK/Eu (asprin)3phen blend as the light emitting layer, the emission of Eu^3 in the PVK/Th0.5Eu0.5(asprin)3 phen blend is great-ly enhanced along with the quenching of the emission of PVK.     

Synthesis, crystal structure and characterization of one-dimension complex constructed by terbium(Ⅲ) and 2-iodobenzoate

The complex of [Tb(2-IBA)3(H2O)2]n (2-IBA=2-iodobenzoate) was prepared by solvent method from TbCl36H2O and 2-iodo-benzoic acid. The crystal structure was determined with X-ray single-crystal diffraction. The X-ray diffraction analysis indicated that the title complex crystallized in triclinic crystal system and Pi space group. The Tb3+ ion was coordinated by six oxygen atoms from five 2-IBA ligands and two oxygen atoms from two water molecules, giving a distorted square-antiprism polyhedral geometry. The carboxyl groups were bonded to the Tb3+ ions with bidentate-bridging and bidentate-chelating coordination modes. The adjacent Tb3+ ions were linked by two bidentate-bridging 2-IBA ligands, forming I-D chain structure. The fluorescence spectrum of the complex showed four main peaks at 489, 543, 587, and 618 nm, Corresponding to 5D4→7F (J=6-3) transition emissions of the Tb3+ ion, respectively.     

Synthesis, Structure and Fluorescence Properties of Tb(Ⅲ) Complex with Isonicotinic Acid and Biphenyl-2,2''-Dicarboxylic Acid

Terbium perchlorate reacted with isonicotinic acid (Hpya) and biphenyl-2,2'-dicarboxylic acid (H2dpa) under hydrothermal condition, a new ternary terbium complex [Tb(pya)(dpa)(H2O)]n (1) was synthesized. The structure of the ternary complex was determined by X-ray single crystal diffraction and characterized by elemental analysis, fluorescence measurement. The fluorescence spectrum shows the title complex emits strong green light. The crystal data for the complex: monoclinic, P21/n space group, a=0.8908(5) nm, b=1.0569(6) nm, c=2.0969(11) nm, β=98.446(8)°, V=1.9528(18) nm3, Z=4, R=0.0241, wR2=0.0534. The center Tb3 ion is eight coordinated. The coordination polyhedron around Tb3 ion can be described as a distorted square antiprism. The complex forms an infinite one-dimensional alternating chain polymer by bridging carboxyl groups of pya and dpa.     

Hydrothermal Synthesis and Characterization of Pyrochlore Titanate R2Ti2O7(R=Gd3+, Tb3+, Dy3+)

Pyrochlore titanate oxides, R2Ti2O7(R=Gd3+, Tb3+, Dy3+), were synthesized under mild hydrothermal conditions. The crystal growth of pyrochlore titanate oxides and taking place of chemical reaction in the hydrothermal processing were sensitive to the alkalinity, temperature, reaction time, the nature of the rare earth ion and the composition of initial reaction mixture. The as-prepared samples were characterized by powder X-ray diffraction, scanning electron microscopy, Raman spectrum and variable temperature dc magnetic susceptibility(Superconductivity quantum interference device, SQUIDS). The magnetic studies gave 7.29×10-23 A·m2/Gd3+ and -8.28 K, 8.75×10-23 A·m2/Tb3+ and -19.7 K, and 8.85×10-23 A·m2/Dy3+ and 0.84 K effective moments and Weiss constants for Gd2Ti2O7,Tb2Ti2O7 and Dy2Ti2O7, respectively.     

Luminescence Characteristic of a New Novel Coprecipitate Rare Earth Complexes

Organicelectroluminescence (OEL)hasbeenex tensivelystudiedbecauseoftheirpotentialapplicationinflatpaneldisplayssincethefirsttwo layerOELde vicewithhighefficiencyandluminancewasfabricatedin 1987[1～ 3] .Rareearth (RE)metalcomplexeshavesomegoodcharacteristics ,suchasextremelynarrowe missionbandsandhighinternalquantumefficiencies ,whicharesuitableforuseastheemissionmaterialsinOEL[4 ] .Tb3+complexwasfirstintroducedintoOELdevices ,andsharpgreenemissionfromTb3+ionhasbeenobserved[5] .Sincethen …     

铽在硫氧化镧基质中的光致发光

采用高温固相反应法制备了La2O2S∶Tb3+、La2O2S∶Tb3+,RE3+(RE=Dy,Gd,Ce,Sm)荧光粉样品并进行了相关表征。结果表明,合成样品的晶体结构与La2O2S相同,为六方晶系;荧光粉颗粒的形貌多为长方形片状;发射光谱由494 nm、545 nm、587 nm、622 nm的一系列锐发射峰组成。研究发现Tb3+的掺杂浓度对样品主发射峰545 nm的发光强度影响很大,且在摩尔分数x(Tb3+)=0.02时达到最强。稀土离子Dy3+、Gd3+对La2O2S∶Tb3+荧光粉的发光有明显的敏化作用。     

Research on Performance of ZnS∶TbF_3 Thin Film Electroluminescence Device

Ｅｌｅｃｔｒｏｌｕｍｉｎｅｓｃｅｎｃｅ (ＥＬ)ｄｅｖｉｃｅｓａｒｅａｖａｉｌａｂｌｅｆｏｒｃｏｍｐｌｅｔｅｓｏｌｉｄｄｉｓｐｌａｙｓ .Ａｌａｒｇｅａｒｅａｄｉｓｐｌａｙｃａｎａｌｓｏｂｅｅａｓｉｌｙｒｅａｌｉｚｅｄｂｙｔｈｅｕｓｅｏｆｔｈｅｓｅｄｅｖｉｃｅｓ .Ｂｅ ｃａｕｓｅｏｆｔｈｅｉｒｈｉｇｈｂｒｉｇｈｔｎｅｓｓａｎｄｌｏｎｇｌｉｆｅ ,ｍａｎｙｓｔｕｄｉｅｓｈａｖｅｒｅｃｅｎｔｌｙｂｅｅｎｍａｄｅｏｆｔｈｉｎ ｆｉｌｍＥＬｄｅ ｖｉｃｅｓｃｏｎｓｉｓｔｉｎｇｏｆａＺｎＳ∶Ｔｂｌａｙｅｒｓａｎｄｗ…     

Synthesis and Luminescent Properties of (Ce0.67-xGdx Tb0.33 ) MgAl11O19 Phosphors

Phosphors with ( Ce0. 67 -xGdxTb0. 33 ) MgAl11 O19 (0 ≤ x ≤0.37 ) composition were prepared by sol-gel processing. The preparation process, crystal structure and luminescent properties of the phosphor powders were investigated.The excitation spectrum is characteristic of Ce3+ ion, while the emission spectrum is composed of lines from Tb3+ ion with main emission peaks at around 542 nm and 487 nm. As the Gd3 + concentration increases, the luminescent intensity at about 542 nm increases to a maximum when x is about 0.12 and then decreases again at higher concentration of Gd3 +ion, whereas, the luminescence at about 487 nm follows the contrary rule.     

Synthesis,characteristic and intramolecular energy transfer mechanism of reactive terbium complex in white light emitting diode

A reactive Tb(III) complex with 2-aminobenzoic acid(2-ABAH) and acrylonitrile(AN) as ligands was synthesized.The structure of the complex was characterized by elemental analysis and Fourier transform infrared spectrometry(FT-IR).The results indicated that the ligands were coordinated with Tb(III) ion.Thermal gravity-derivative thermogravimetric(TG-DTG) analysis indicated that the complex kept stable up to 198 oC.Luminescence properties were investigated by UV-vis absorption spectra and fluorescence spectra.The results suggested that being excited at 361 nm,the complex exhibited characteristic emission of Tb(III) ion,revealing that the complex could be excited by 365 nm ultraviolet chip.The HOMO and LUMO,ΔE(HOMO-LUMO),molecular frontier orbital,and the singlet state and triplet energy state levels of the ligands were calculated at the B3LYP/6-31+G(d) level.The results indicated that intramolecular energy transfer mechanism followed Dexter exchange energy transfer theory.Both the calculation for excited state of ligand and energy transfer mechanism could provide the theoretical basis for the design of high luminescent materials of rare earth complexes with organic ligands.