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。
简介:Er^3+-dopedSrBi4Ti4O15-Bi4Ti3O12(SBT-BIT-xEr^3+,x=0.00,0.05,0.10,0.15and0.20)inter-growthceramicsweresynthesizedbythesolid-statereactionmethod.Structural,electricalandup-conversionpropertiesofSBT-BIT-xEr^3+wereinvestigated.Allsamplesshowedasinglephaseoftheorthorhombicstructure.RamanspectroscopyindicatedthattheEr^3+substitutionforBi^3+atAsitesofthepseudo-perovskitelayerincreasesthelatticedistortionofSBT-BIT-xEr^3+ceramics.ThesubstitutionofBi^3+byEr^3+leadstoadecreaseofdielectriclosstanδandanincreaseofconductivityactivationenergy.Piezoelectricconstantd33wasslightlyimproved,butdielectricconstantwasdecreasedwiththeEr^3+doping.TheSBT-BIT-xEr^3+ceramicwithx=0.15exhibitstheoptimizedelectricalbehavior(d33~17pC/N,tanδ~0.83%).Moreover,twobrightgreen(532and548nm)andonered(670nm)emissionbandswereobservedunderthe980nmexcitation.Optimizedemissionintensitywasalsoobtainedwhenx=0.15fortheSBT-BIT-xEr^3+ceramic.Therefore,thiskindofceramicsoughttobepromisingcandidatesformultifunctionaloptoelectronicapplications.
简介:Na5+xYAlxSi4-xO12superionicconductorsarerhombohedralR3cspacegroup.Theirstructuresarecharacterizedby(Alx/4Si1-x/4)O4tetrahedralinkedtoformpuckered(Al3xSi4-x)4O35ringsparalleltothebasalplaneofthehexagonalcell.Theserings,separatedbypartsofsodiumoxygenpolyhedron,arestackedtoformlargerigidcolumsparalleltocaxis.Thecolumnsarelinkedby[YO6]octahedratoformathree-dimensionalFrameworkwithlargechannelsbetweentherings.PartsofNaionslocatedinthecoresofthecolumnsaremovable.Intermsoftheconductionmechanism,theconcentrationofconductingNa+ionswascarriedoutandcomparedwiththeexperimentalresults.Itwasfoundthatthetheoreticalvaluesaccordwiththeexperimentalresults.
简介:Inthisstudy,Almatrixcompositesreinforcedby7.5and15vol.%B4CparticlesandalsomonolithicAl(AlwithouttheB4Cparticles)wereproducedbywetattritionmillingandsubsequenthotforwardextrusionprocesses.Themicrostructureofthecomposites,evaluatedbyscanningelectronmicroscopy(SEM),showedthattheB4CparticleswereproperlydistributedintheAlmatrix.MechanicalpropertiesoftheAI/B4CcompositesandmonolithicAlwereinvestigatedbytensile,wearandhardnesstests.TheresultsrevealedthatwithincreasingcontentofB4Cparticles,thetensilestrengthandmicrohardnessofcompositesincreasedbuttheelongationdecreased.Inaddition,thetensilestrengthandmicrohardnessofcompositesampleswerehigherthanthoseofmonolithicAl.ThedensitymeasurementsrevealedthatthedensityofcompositesdecreasedwithincreasingcontentoftheB4Cparticles.
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简介:采用柠檬酸络合和浸渍两步法制备了一系列B-xMo共掺杂BiVO4可见光光催化剂,并采用XRD、XPS、SEM、EDS、BET和UV-vis等表征和分析。以降解甲基橙(MO)、亚甲基蓝(MB)、金橙Ⅱ号(AOⅡ)和罗丹明B(RhB)溶液为指针反应,考察掺杂对BiVO4可见光催化活性的影响。结果表明:B-Mo共掺杂能抑制BiVO4晶粒生长,比表面积增大,共掺杂后BiVO4禁带宽度窄化,且氧空位较单掺杂增加。当Mo掺杂量为2.5%(原子分数)时制备的B-2.5Mo-BiVO4对甲基橙的降解率达96%左右,且该样品也能有效降解亚甲基蓝(MB)、金橙Ⅱ号(AOⅡ)和罗丹明B(RhB)溶液。
简介:Withpositronannihilationradiationonedimensionangular-correlationdevice,itismeasuredthatpositronannihilationradiationonedimensionangular-correlationcurvesofpolycrystalsodiumionconductorNa5Y1-xCrxSi4O12(NYCS)system.Afterelectronmomentumdistributioncurvesarenormalized,linearparametersarecalculated.TheparametersH,WandSshowthechangeofNa+ionvacancyconcentrationinNYCSseriessamples.TheresultsshowthatparametersH,WandSofonedimensionangular-correlationcurvesofthosesamplesvarygreatlywithCr2O3contents.WithCr2O3contentincreasing,HandSparametersincrease,butWdecreases,andreachesextremesatx=0.05;thenwithCr203addingcontinually,parametersHandSdecreasegradually,parameterWincreasesgradually.Thisshowsthat,inaddtiontoCr2O3,theconductivityhascloserelation