G.L. Li
,
X.M. Meng
,
F. T. Zhang and Y.K. Wu (Laboratory of Atomic Imaging of Solids
,
Institute of Metal Research
,
Chinese Academy of Sciences
,
Shenyang 110015
,
China)
金属学报(英文版)
The atomic level structures of fcc/bcc interfaces in an Fe-9Ni alloy have been examined by means of HREM. It has been found that the orientation of γ /α interface had great effects on its atomic structure. These interfaces with different orientations may be composed of only structural ledges, structural ledges with misfit dislocations,superledges with misfit dislocations or only misfit dislocations. A structural model of growth ledge was suggested. The terrace of growth ledge was composed of structuralledges or misfit dislocations. The atomic structure of the riser of growth ledge was the same as that of the side facet of γlath, which is composed of saperiedges with misfitdislocations.
关键词:
Fe-9Ni alloy
,
null
,
null
,
null
,
null
Physica C-Superconductivity and Its Applications
Superconducting cuprate fluorides Nd0.7Sr1.3Cu(O,F)(4-delta) with T-c = 44 K were obtained by solid phase fluorination of the T-structure Nd0.7Sr1.3CuO4-gamma at low temperature (200-300 degrees C) using CuF2 as fluorinating reagent. The oxyfluoride has K2NiF4 structure with S.G. I4/mmm as its precursors, but the evident lattice expansions were observed. The a-axis expands from 3.7257(2) Angstrom to 3.9288(5) Angstrom and c-axis from 12.8240(3) Angstrom to 12.9630(2) Angstrom. No trace of SrF2 was detected in these fluorinated products. XRD and magnetic measurement revealed that the superconductivity in the fluorinated products originated from the oxyfluorides with reduced CuO2 plane and in the presence of the apical anion.
关键词:
hole concentration;copper;route;a=ca;tc
郝庆兰
,
白亮
,
李莹
,
李雪
,
相宏伟
,
李永旺
催化学报
用喷雾干燥法制备了微球状Fe/Cu/K/SiO2催化剂,并在不同的反应条件下对其在浆态床F-T合成反应中的催化性能进行了评价. 结果表明,反应温度和原料气H2/CO比的调变对催化剂运行稳定性的影响较大,反应初始阶段加入的液体石蜡介质对催化剂运行稳定性的影响不大. 原料气空速的增加可有效地提高反应的总烃时空产率,但同时CO转化率会明显降低,且重质烃选择性下降; 低H2/CO比的原料气有利于在保持合适的转化率的同时提高重质烃的选择性,并可明显提高总烃的时空产率; 提高系统压力可增大催化剂的催化活性,改善重质烃的选择性; 而提高反应温度尽管可明显提高催化剂活性,但同时也会促进WGS反应的发生,降低重质烃的选择性. 因此,浆态床F-T合成反应中操作参数的适当调变可使催化剂活性、产物烃分布和烃产率得到有效优化,最大限度地获得目的产物.
关键词:
费-托合成
,
铁基催化剂
,
浆态床反应器
,
喷雾干燥技术
金属学报(英文版)
粒裕希停桑谩。疲希遥茫拧。停桑茫遥希樱茫希校佟。希拢樱牛遥郑粒裕桑希巍。希啤。停粒牵危牛裕遥希巍。樱校眨裕裕牛遥牛摹。粒蹋眨停桑危眨停樱桑蹋桑茫希巍。粒蹋蹋希佟。疲桑蹋停?##2##3##4##5ATOMICFORCEMICROSCOPYOBSERVATIONOFMAGNETRONSPUTTEREDALUMINUM-SILICONALLOYFILMSJ.W.Wu,J.H.FangandZ.H.Lu(NationalLaboratoryofMoleculeandBiomoleculeElectronics,SoutheastUniversity,Nanjing210096,ChinaManuscriptreceived27October1995)Abstrcat:Twodifferentsurfacemorphologycharacteristicsofmagnetronsputteredaluminumsilicon(Al-Si)alloyfilmsdepositedat0and200℃wereobservedbyatomicforcemicroscopy(AFM).Oneisirregularlyshapedgrainsputtogtheronaplane.TheotherisirregularlyshapedgrainsPiledupinspace.Nanometer-sizedparticleswithheightsfrom1.6to2.9nmwerefirstobserved.Onthebasisoftheseobservationsthegrowthmechanismofmagnetronsputteredfilmsisdiscussed.Keywords:magnetronsputtering,Al-Sialloy,surfacemorphology,atomicforcemicroscopy,filmgrowthmechanism1.IntroductionTheuseofaluminumalloys[1,2],inparticularAl-Si,isacommonfeatureinmanysinglelevelandmultilevelinterconnectionschemesadoptedinthemanufactureofmicroelectronicdevicesbecauseofseveraldesirableproperties.TheAl-Sigrainmorphology(size.geometryanddistributionofgrainsisassociatedwithstepcoverage[3],electromigration[4]andinterconnectsresistivity[5]etc..Thus,characterizationofAl-Sialloysurfacemorphologyisveryimportant,especiallywhenintegratedintensityincreasesandlinewidthsof0.3to0.5μmbecomecommon.Inthepasttwentyyears,theAl-Sialloysurfacemorphologywhichaffectsthereliabilityofmicroelectronicdeviceshasbeenwidelyinvestigatedbyscanningelectronmicroscopy(SEM),transmissionelectronmicroscopy(TEM)etc.[5-7].However,SEMandTEMhavetheirlimitationorinconvenience,forexample,theverticalresolutionofSEMisnothighandTEMneedscomplexsamplepreparation.Recently,anewgrainboundaryetchingmethodwasproposed￣[8]whichalsoneedstroublesomechemicaletching.Atomicforcemicroscopy(AFM),sinceitsemerging,hasbecomemoreandmoreusefulinphysics,chemistry,materialsscienceandsurfacescience,becauseofitshighresolution,easeofsamplepreparationandrealsurfacetopography.Recently,discussion[9,10]waspresentedonhowAFMwillplayaroleinsemiconductorindustry.Asaresponsetothisdiscussion,weusedAFMtoinvestigateAl-SialloysurfacemorphologyandhaveobtainedsomeresultswhichcannotberevealedbySEMorTEM.ThisindicatesthatAFMisagoodcharacterizationtoolinsemiconductorindustry.2.SamplePreparationInourexperiments,aluminumwith30ppmsiliconwassputteredonsiliconsubstrateinbatchdepositionmodeAllthreefilmswiththicknessof1.6μmweredepositedusinganargonsputteringpressureof4.2×10￣-3Pa.TheotherdepositionparametersaredescribedinTable1.Thesubstratewascleanedusingstandardpremetallizationcleaningtechniquespriortofilmdeposition.3.ExperimentalResultsandDiscussionTheAFMmeasurementswereperformedonacommercialsystem(NanoscopeIII,DigitalInstruments,SantaBarbara).Thetipismadeofmicrofabricatedsiliconnitride(Si_3N_4)Itisattachedtoa200μmcantileverwithaforceconstantofabout0.12N/m.Beforethesurfaceofsamplewasexamined.agoodtipwithananometer-sizedprotrusionatitsendwasselectedbeforehand,whichcanbeobtainedbyimagingtheatomicstructureofmicasubstrateandagoldgrid.AtypicaloperatingforcebetweenthetipandAl-Sisamplesurfaceisoftheorderof10￣-8Nandallimagesweretakenatroomtemperatureinair.AtypicaltopographicviewoftheAl-SifilmsisshowninFig.1(allimagescansizeis5by5μma,bandcarerespectivelyforsample1,2,and3).FromFig.la,itcanbeseenthatirregularlyshapedgrainstiltinginvaryingdegreespileupinspace,andgroovesamongtheirregularlyshapedgrainsaredifficulttodecideatacertainarea(wedefineitascharacteristicA).Toourknowledge,onreportsonthesurfacemorphologyhavebeenpresentedbefore.InFig1b,however,irregularlyshapedgrainsassembleonaPlaneandgroovesamongtheirregularlyshapedgrainsareeasytodecide(wedefineitascharacteristicB),whichisinagreementwithmanypreviousreports[5-7].InFig.1c,bothcharacteristicA(arrowA)andcharacteristicB(arrowB)wereobserved.IndoingAFMexperiments,weselectedfivedifferentscanareastobeimagedforeachsampleandfoundthatallimagesofeachsamplearerespectivelysimilartoFig.1a,bandc.Also,wenotedthatthesurfaceofinFig.1a.WethinkthatdepositionparameterswillinfluenceAl-Sisurfacemorphology,andthetiltedgrainsmaybesusceptibletomicrocracking.Byreducingthescansizeareato2by2μm(Fig.2aandb).Weobtainedmanyidenticalresultsasdescribedabove,suchasirregularlyshapedgrainsetc.Forthefirsttime,wefoundnanometersizedparticlesonirregularlyshapedgrainsurfacewhichcannotberevealedbySEMbecausethediameterofthesenanoparticlesisabout10nmandtheheightofthesenanoparticlesisintherangeof1.6to2.9nm.Inimaging,wenotedthatrotatingthescandirectionandchangingthescanfrequencydidnotaffectthestructureofthesegrainsasshowninFig.2aandb,rulingoutthepossibilitythatscanninginfluencedtheshapeoftheseparticlesorcausedsomesimilarimagingartifacts.Also,wenotedthatthenanoparticleswerenotobservedontheslopesofthegrooves(Fig.2aandb).Thisphenomenoncanbeexplainedasfollows:thepotentialenergyattheslopeislargerthanthatelsewhere,sotheparticlesseemmorelikelytobedepositedontheseareaswithlowerpotentialenergy.Fig.2c,scansize250by250nm,isazoomtopographicimage(whiteoutlineinb).Itshowsunevendistributionofthenanoparticles.Andtheheightdifferenceofthenanoparticlesindicatesdifferentgrowingspeed.Wethinkbasedonthemorphologyofnanoparticles,thattheheightdifferenceandunevendistributionofthesenanoparticlesshowdifferentgrowingadvantageandindicatethatatomshaveenoughenergytomovetoasuitablegrowingspot.Theenergymaybefromthefollowingsources:surfacetemperaturefluctuation,stressdifferenceorcollisionbetweenhighspeedsputteredatoms.Thesenanoparticlesgoongrowingandformmanyirregularlyshapedgrains.AndtheseirregularlyshapedgrainsfurtherconnecteachotheraccordingtocharacteristicAorB,finallyformingtheAl-Sisurfacemorphology.4.ConclusionWecandrawthefollowingconclusionsfromtheabove.First,theexperimentalresultsshowedthatAFMisapowerfultooltoinvestigatethedetailsofAl-Sisurfacemorphologywhichcangreatlyenrichourknowledgeofthefilmgrowthmechanism.Second,depositionconditionsplayanimportantroleindeterminingtheAl-Sisurfacemorphology.Third,thetwoAl-Sisurfacemorphologycharacteristicsarethatirregularlyshapedgrainsassembleonaplaneandirregularlyshapedgrainstiltinginvaryingdegreespileupinspace.Fourth,forthefirsttime,nanoparticleswereobservedonirregularlyshapedgrainsurfacewhichsuggestedthatthefilmgrowthmechanismwasbyinhomogeneousnucleation.Acknowledgements-BeneficialdiscussionswereheldwithDr.ZhenandMr.Zhu.ThisworkwaspartiallysupportedbytheNationalNaturalScienceFoundationofChina.RFFERENCES｜｜1D.pramanikandA.N.Saxena,SolidStateTechnol.26(1983)127.2D.pramanikandA.N.Saxena,SolidStateTechnol.26(1983)131.3D.pramanikandA.N.Saxena,SolidStateTechnol.33(1990)73.4S.S.IyerandC.Y.Worg,J.Appl.phys.57(1985)4594.5J.F.Smith,SolidStateTechnol.27(1984)135.6D.GerthandD.Katzer,ThinSolidFilm208(1992)67.7R.J.WilsonandB.L.Weiss,ThinSolidFilm207(1991)291.8E.G.Solley,J.H.Linn,R.W.BelcherandM.G.Shlepr,SolidStateTechnol33(1990)409I.SmithandRHowland,SolidStateTechnol.33(1990)53.10L.Peters,SemiconductorInternational16(1993)62.##61D.pramanikandA.N.Saxena,SolidStateTechnol.26(1983)127.2D.pramanikandA.N.Saxena,SolidStateTechnol.26(1983)131.3D.pramanikandA.N.Saxena,SolidStateTechnol.33(1990)73.4S.S.IyerandC.Y.Worg,J.Appl.phys.57(1985)4594.5J.F.Smith,SolidStateTechnol.27(1984)135.6D.GerthandD.Katzer,ThinSolidFilm208(1992)67.7R.J.WilsonandB.L.Weiss,ThinSolidFilm207(1991)291.8E.G.Solley,J.H.Linn,R.W.BelcherandM.G.Shlepr,SolidStateTechnol33(1990)409I.SmithandRHowland,SolidStateTechnol.33(1990)53.10L.Peters,SemiconductorInternational16(1993)62.##A##BATOMIC FORCE MICROSCOPY OBSERVATION OF MAGNETRON SPUTTERED ALUMINUM-SILICON ALLOY FILMS$$$$J.W.Wu,J.H. Fang and Z.H.Lu (National Laboratory of Molecule and Biomolecule Electronics,Southeast University,Nanjing 210096, China Manuscript received 27 October 1995)Abstrcat:Two different surface morphology characteristics of magnetron sputtered aluminumsilicon(Al-Si)alloy films deposited at 0 and 200℃ were observed by atomic force microscopy(AFM).One is irregularly shaped grains put togther on a plane.The other is irregularly shaped grains Piled up in space. Nanometer-sized particles with heights from 1.6 to 2.9 nm were first observed. On the basis of these observations the growth mechanism of magnetron sputtered films is discussed.
关键词:
:magnetron sputtering
,
null
,
null
,
null
,
null
Physics Letters A
Except for a Peierls transition at T(p) = 180 K, a new transition around T = 270 K in K0.3MoO3 single crystals has been found as evidenced by the anomalies in electrical, magnetic and thermodynamic properties. This transition may be caused by the variation of carrier characteristics or of the charge transfer between cations and anions.
关键词:
庞涛
,
周元
功能材料
doi:10.3969/j.issn.1001-9731.2017.04.023
采用简单的水热工艺制备了六方相Na(Y1.5 Na0.5)F6∶Eu3+荧光粉.300 K温度下利用394 nm光波长激发,观察到Eu3+的5Dn(n=0,1,2)→7 FJ(J=1,2,3,4)跃迁,对应主波长590 nm,色彩饱和度约为0.97.当温度升高到420 K时,仅观察到微小的色漂移.进一步拟合Ln(I0/I-1)和10 000/T的关系曲线,确定发光的热猝灭激活能约为0.324 eV.良好的热稳定性,表明Na(Y15Na0.5)F6∶Eu3+适合于功率器件的封装.在Na(Y1.5 Na0.5)F6∶Eu3+表面包覆二氧化硅后,可观察到Eu3+增强的发光,但这种荧光增强依赖于二氧化硅壳层的厚度.利用荧光增强与荧光猝灭的竞争模型解释了上述现象.
关键词:
Na(Y1.5 Na0.5)F6∶Eu3+
,
热稳定性
,
SiO2包膜
,
荧光增强
滕波涛
,
常杰
,
万海军
,
鲁继青
,
郑绍成
,
刘亚
,
刘颖
,
郭小惠
催化学报
考虑了烯烃、醇与酸的再吸附及其非本征效应(烯烃、醇与酸在催化剂孔道中的扩散作用、物理吸附及溶解度效应)对产物分布的影响,推导了基于详细反应机理的亚甲基插入的烷基机理F-T合成校正综合动力学模型.利用文献数据对动力学模型进行了回归,获得了与文献报道结果相一致的动力学参数.由校正动力学模型计算的烷烃、烯烃、醇与酸产物分布及烯烃比、醇烃比及酸烃比与实验数据较好地吻合.动力学计算结果表明,在铁锰催化剂上,烷烃、烯烃、醇与酸生成的反应是平行竞争反应,烯烃、醇与酸在催化剂表面的再吸附及二次反应导致产物分布偏离了ASF分布.动力学研究还表明,相同碳数的醇与酸产物在催化剂表面上再吸附及二次反应的机会比相同碳数的烯烃大.通过比较相同碳数的烯烃、醇与酸的分子体积及沸点,指出了在铁锰催化剂上,低碳数的烯烃、醇与酸的再吸附及二次反应对产物分布影响的非本征效应中,烯烃、醇与酸的扩散阻力不是主导效应.
关键词:
费托合成
,
动力学模型
,
产物分布
,
烃
,
含氧化合物
Journal of Physics-Condensed Matter
We discuss the interaction between two-level systems and the phonon field in non-crystalline dielectric solids, and we calculate the quantum transition matrix elements of such an interaction. After studying the Boltzmann equation for phonon transport, we obtain the phonon distribution function. From a direct calculation of the heat current, and as a result of obtaining the thermal conductivity of non-crystalline dielectric solids, the T2 relation is obtained.
关键词:
heat
王艺慈
,
罗果萍
,
柏京波
,
郝志忠
,
邬虎林
钢铁
采用差热分析（DTA）与X射线衍射（XRD）相结合的方法，研究了高碱度烧结矿中F、K、Na对烧结固相反应开始温度与最初形成产物的影响规律，研究结果表明：烧结原料中F、K、Na的存在，促进了烧结固相反应过程中低熔点化合物硅酸钠、铁酸钠、枪晶石的形成，固相反应过程中硅酸钠自702 ℃，铁酸钠自780 ℃，枪晶石自900 ℃开始合成，从而探明了F、K、Na在烧结固相反应过程中的行为规律。
关键词:
烧结固相反应;固相反应开始温度;最初形成产物
王艺慈
,
罗果萍
,
柏京波
,
郝志忠
,
邬虎林
钢铁
采用差热分析(DTA)与X射线衍射(XRD)相结合的方法,研究了高碱度烧结矿中F、K、Na对烧结同相反应开始温度与最初形成产物的影响规律,研究结果表明:烧结原料中F、K、Na的存在,促进了烧结固相反应过程中低熔点化合物硅酸钠、铁酸钠、枪晶石的形成,固相反应过程中硅酸钠自702℃,钦酸钠自780℃,枪晶石自900℃开始合成,从而探明了F、K、Na在烧结固相反应过程中的行为规律.
关键词:
烧结固相反应
,
固相反应开始温度
,
最初形成产物
