简介:第三产生同步加速器X光象自然材料一样为许多设计材料的微结构描述提供一个崭新的机会。这篇文章为结构的材料的学习表明三种技术的用法:微分孔的X光检查显微镜学(DAXM),三维的X光检查衍射(第3DX),和散布的同时的宽angle/small角度X光检查(蜡/萨克斯风管)。DAXM能与高空间、尖的分辨率在多晶的材料测量3D谷物结构。在使变形的材料,streaked衍射山峰能被用来在单个谷物分析本地脱臼内容。比作DAXM,第3DX能大批印射谷物材料更快速在损坏空间分辨率的情况下。当材料在变丑下面时,发展微观结构,为学习是很有用的。蜡/萨克斯风管对与不同类的结构学习材料合适,例如猛抛加强的合金。蜡和萨克斯风管揭示的结构的信息能为更深的卓见被合为材料行为。这三种技术的未来开发和应用程序将也被讨论。
简介:Intrinsiccarrierconcentration(ni)isoneofthemostimportantphysicalparametersforunderstandingthephysicsofstrainedSiandSi1-xGexmaterialsaswellasforevaluatingtheelectricalpropertiesofSi-basedstraineddevices.Uptonow,thereportonquantitativeresultsofintrinsiccarrierconcentrationinstrainedSiandSi1-xGexmaterialshasbeenstilllacking.Inthispaper,byanalyzingthebandstructureofstrainedSiandSi1-xGexmaterials,boththeeffectivedensitiesofthestatenearthetopofvalencebandandthebottomofconductionband(NcandNv)at218,330and393KandtheintrinsiccarrierconcentrationrelatedtoGefraction(x)at300KweresystematicallystudiedwithintheframeworkofKPtheoryandsemiconductorphysics.ItisfoundthattheintrinsiccarrierconcentrationinstrainedSi(001)andSi1-xGex(001)and(101)materialsat300KincreasessignificantlywithincreasingGefraction(x),whichprovidesvaluablereferencestounderstandtheSibasedstraineddevicephysicsanddesign.
简介:ThetransportpropertiesintheLa2/3(Ca1-xSrx)1/3MnO3(x=0,1/3,2/3)filmspreparedusingtheRFmagnetronsputteringmethodwereinvestigated.TheeffectoftheCa,Srdouble-dopingattheApositionintheLa2/3A1/3MnO3onthestructureofthetargetsandtransportofthefilmshasbeenstudied.Withtheincreaseofx,thestructuresofthetargetstransformfromtherhombohedralphasetothecubicphase;themetal-insulatorphasetransitiontemperature(Tp)ofthefilmsincreases;andthecorrespondingpeakresistivitydecreases.Allthephenomenacanbequalitativelyexplainedbythelatticeeffect.
简介:TechnologicalprocessofrareearthsealinganodizedLY12(2024)alloyisintroduced.Corrosionbehaviorofthefilmwasstudiedbypolarizationcurvesandelectrochemicalimpedancespectroscopy(EIS).Theresultsshowedthatthecoatingremainedpassivityatthepotentialrangefromtheopencircuitpotential(-780mV)to-250mVinNaClsolution.Whenthepotentialexceeded-200mV,corrosionreactionhappenedonthecoating.theresultsofElSanalysiswasconsistentwiththeresultsofpolarizationcurves.
简介:Themicrostructuralevolutionsofadvanced9-12%Crferrite/martensiteheat-resistantsteelsusedforpowergenerationplantsarereviewedinthisarticle.Despiteofthesmalldifferencesinchemicalcompositions,thesteelssharethesamemicrostructureoftheas-temperedmartensite.Itisthethermalstabilityoftheinitialmicrostructurethatmattersthecreepbehavioroftheseheat-resistantsteels.Themicrostructuralevolutionsinvolvedin9-12%Crferriteheat-resistantsteelsareelabo-rated,including(1)martensiticlathwidening,(2)disappearanceofprioraustenitegrainboundary,(3)emergenceofsubgrains,(4)coarseningofprecipitates,and(5)formationofnewprecipitates,suchasLaves-phaseandZ-phase.Theformerthreemicrostructuralevolutionscouldberetardedbyproperlydisposingthelattertwo.Namelyimprovingthestabilityofprecipitatesandoptimizingtheirsizedistributioncaneffectivelyexertthebeneficialinfluenceofprecipitatesonmicrostructures.Inthissense,themicrostructuralstabilityofthetemperedmartensiteisinfactthestabilityofprecipitatesduringthecreep.Manyattemptshavebeencarriedouttoimprovethemicrostructuralstabilityof9-12%Crsteelsandseveralpromisingheat-resistantsteelshavebeendeveloped.
简介:在电的运输性质上评估Ni替换的影响,p类型skutteruditesRyFe3NiSb12(R=Ba,Nd和Yb)系统地从2.5K被调查到800K。由小心地修改三fillers,Ba,Nd和Yb的充满的部分,搬运人集中精确被调整,它按比例改变到数统治的原子价计算的名字的价值。活动性和Seebeck系数的搬运人集中依赖表示在原子价乐队的二乐队贡献,和为热电的性能的优化搬运人集中在之间(5–9)×1020厘米−3。样品的热电导率用稀土元素的元素(Nd和Yb)填满的格子作为与相比显著地更低充满Ba,由于更低的反响的频率并且部分充满。与公司替换相比,Ni替换趋于关上乐队差距,它为RyFe3NiSb12。然而由于状态的密度的改进,当搬运人集中是类似的时,RyFe3NiSb12比RyFe2公司2在更低的温度范围的Sb12。0.73的ZT价值为Yb0.77Fe3在600K的NiSb12。