简介：采用水热法制备平均粒度约300nin的六方相Bi2Te3纳米粉末。再以Bi2Te3粉末为原料，采用封管熔炼法制备N型（Bi2Te3）0.9（AgxBi2-xSe3）0.1（x为Ag的摩尔分数。x=0.1，0.2，0.3，0.4）合金粉体材料，通过快速热压制备N型（Bi2Te3）0.9（AgxBi2-xSe3）0.1块状热电材料。在300~550K温度范围内研究该材料的热电性能与Ag掺杂量之间的关系，以及热压工艺对材料热电性能的影响。结果表明在775K，40MPa条件下烧结20min后材料的相对密度达到97％以上，晶粒大小在3gm左右。当Ag掺杂量x=0.2时，在300K温度下热导率达到最小值0.71W／mK，同时获得最高的热电优值（ZT值）1.07。

简介：Wereporteddiversesolitonoperationsinathulium/holmium-dopedfiberlaserbytakingadvantageofataperedfiber-basedtopologicalinsulator（TI）Bi2Te3saturableabsorber（SA）.TheSAhadanonsaturablelossof53.5%andamodulationdepthof9.8%.Stablefundamentallymode-lockedsolitonsat1909.5nmwithdistinctKellysidebandsontheoutputspectrum,apulserepetitionrateof21.5MHz,andameasuredpulsewidthof1.26pswereobservedinthework.Byincreasingthepumppower,bothbunchedsolitonswithsolitonnumberupto15andharmonicallymode-lockedsolitonswithharmonicorderupto10wereobtained.Toourknowledge,thisisthefirstreportofbothbunchedsolitonsandharmonicallymode-lockedsolitonsinafiberlaserat2μmregionincorporatedwithTIs.

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简介：Byusingtheultrasound-assistedliquidphaseexfoliationmethod,Bi2Te3nanosheetsaresynthesizedanddepositedontoaquartzplatetoformakindofsaturableabsorber（SA）,inwhichnonlinearabsorptionpropertiesaround2μmareanalyzedwithahome-mademode-lockedlaser.Withtheas-preparedBi2Te3SAemployed,astablepassivelyQ-switchedall-solid-state2μmlaserissuccessfullyrealized.Q-switchedpulseswithamaximumaverageoutputpowerof2.03Waregeneratedunderanoutputcouplingof5%,correspondingtothemaximumsingle-pulseenergyof18.4μJandpeakpowerof23W.Thedeliveredshortestpulsedurationandmaximumrepetitionrateare620nsand118kHzunderanoutputcouplingof2%,respectively.ItisthefirstpresentationofsuchBi2Te3SAemployedinasolid-stateQ-switchedcrystallinelaserat2μm,tothebestofourknowledge.Incomparisonwithother2Dmaterialssuitableforpulsed2μmlasers,thesaturableabsorptionperformanceofBi2Te3SAisprovedtobepromisingingeneratinghighpowerandhigh-repetition-rate2μmlaserpulses.

简介：Inthiswork,Bi2Te3films(250nm)arefabricatedonSiO2/Sisubstratesbyradiofrequency(RF)magnetronsputteringatroomtemperature,andthepreparedfilmsareannealedoverthetemperaturerangeof200°Cto400°C.Crystallinityandelectricalpropertiesofthefilmscanbetunedcorrespondingly.ThepowerfactorsofBi2Te3filmsof0.85μW/K2cmto11.43μW/K2cmwereachievedafterannealing.Theinfraredreflectancemeasurementsfrom2.5μmto5.0μmdemonstratethatthereisalsoaslightred-shiftoftheplasmaoscillationfrequencyintheBi2Te3films.Bymeansofplasmoniccalculations,weattributethered-shiftofabsorptionpeakstothereductionofcarrierconcentrationandthechangeofeffectivemassofBi2Te3filmswiththeincreasedannealingtemperature.

简介：Inthispaper,wereportedamultiwavelengthpassivelyQ-switchedYb3+:GdAl3（BO3）4solid-statelaserwithtopologicalinsulatorBi2Te3asasaturableabsorber（SA）forthefirsttime,tothebestofourknowledge.Bi2Te3nanosheetswerepreparedbythefacilesolvothermalmethod.TheinfluenceofthreeBi2Te3densitiesonthelaseroperationwascompared.Themaximumaverageoutputpowerwasupto57mWwithapulseenergyof511.7nJ.Theshortestpulsewidthwasmeasuredtobe370nswith110kHzpulserepetitionrateand40mWaveragepower.Thelaseroperatedatthreewavelengthssimultaneouslyat1043.7,1045.3,and1046.2nm,ofwhichthefrequencydifferenceswerewithintheterahertzwaveband.OurworksuggeststhatsolvothermalsynthesizedBi2Te3isapromisingSAforsimultaneouslymultiwavelengthlaseroperation.

简介：Duetotheremarkablemagnetoresistance(MR)effectonperovskite-typemanganite,magnetoelectronicsandspintronicshavebecomeattractivesubjectsofexperimentalandtheoreticalinvestigationsfortheapplicationpurpose.(La0.9Nd0.1)2/3Ca1/3Mn1-xFexO3(x=0,x=0.05)werepreparedsuccessfullybysol-gelmethod.Thestructure,magneticproperties,andtransportpropertiesofthecompoundswereinvestigated.Themagnetoresistanceeffectdependsonthecompositionandthetemperature.XRDpatternsshowthatthecompoundisasinglephasepolycrystalwithpseudocubicstructure.Alargenegativeisotropicmagnetoresistanceeffectinthesampleswereobservedatlowtemperatureregion.ThemaximumMRofthesampleswas77%and97%,respectively.Itwasmostlikelyduetothescatteringorthetunnelingtransportofspin-polarizedcarriersinlatticeunderstrongmagneticfield.

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简介：本文制备了Bi2O3-Ni2O3纳米粉末,对其结构进行了表征,并研究了制备的纳米粉末对苯光催化降解的影响因素。结果表明：制备的纳米粉末由Bi2O3和Ni2O3复合而成,经750℃焙烧的光催化剂对苯光催化降解活性最高;水蒸气的加入和氧气的增加,都能促进苯的降解率增大;由Langmuir-Hinshelwood动力学模型得出苯的光催化降解反应的吸附常数和反应速率常数分别为0.1398L·μmol^-1和0.0024μmol·L-1·min^-1。

简介：EffectofMnsubstitutionforFeincubicLavesZr0.1Tb0.9(Fe1-xMnx)2andY0.1Tb0.9(Fe1-xMnx)2com-poundsispresented.Similarresultsinbothsystemsareobtained:ThestructureandthemagnetismofTbFe2arebothinfluencedslightlybyasmallamountofYorZrsubstitutionforTb;Withincreasingxvalue,thelatticeconstantincreasesmonotonously;theCurietemperaturedecreaseslinearly;whilesaturationmagnetizationincreaseslinearly.ForthesmallamountofMnsubstitutionforFeinbothsystems,magnetostrictionissignificantlylargerthanthatinthepureironalloys.Thelargestmagnetostrictionof|γ‖-|γ|=2200×10-6atmagneticfieldof2×107/4πA/misobtainedforY0.1Tb0.9(Fe0.95Mn0.052.

简介：黄磷(Bi1-xSmx)2ZnB2O7(x=0.01，0.03，0.05，0.07，和0.09)被常规稳固的州的反应综合。所有样品的纯净被X光检查粉末衍射(XRD)检查。XRD分析证明所有这些混合物具有Bi2ZnB2O7的一个单个阶段，显示在Bi2ZnB2O7的双性人(3+)能被没有晶体结构的变化的Sm(3+)部分代替。在房间温度的刺激和排放系列显示出Sm(3+)的典型4f-4f转变。主导的刺激线在404nm附近由于(6)H5/2→(4)K11/2和排放光谱在563，599，646，和704nm由一系列线组成由于(4)G5/2→(6)H5/2，(6)H7/2，(6)H9/2，并且(6)H11/2分别地。在Bi2ZnB2O7的Sm(3+)的最佳的集中关于3mol%(相对1mol双性人(3+))并且批评距离Rc作为2.1nm被计算。Bi1.94Sm0.06ZnB2O7的排放紧张的温度依赖在在100和450K之间的温度范围被检验。紧张下降了到起始的紧张的一半的熄灭的温度是280K。为在Bi1.94Sm0.06ZnB2O7的Sm(3+)的一生作为0.29和1.03ms的价值被适合。

简介：采用丝印法在铝基板上制备具有低室温电阻率、适中热敏常数的负温度系数BaCo0.02ⅡCo0.04ⅢBi0.94O3/Ba0.5Bi0.5Fe0.9Sn0.1O3复合热敏厚膜。采用数字多用表、吉时利2400和阻抗分析仪对热敏厚膜的电学性能进行表征。结果表明：随着Ba0.5Bi0.5Fe0.9Sn0.1O3含量从0.05增加至0.25,厚膜的室温电阻率、热敏常数和峰值电压均有所增加且分别处于1.47-26.5Ω·cm、678-1345K和18.9-47.0V范围内,厚膜峰值电压对应的电流也有所降低且处于40-240mA范围。阻抗谱测试表明,这些热敏厚膜表现出非正常的异质电学微结构行为,由高阻态的晶粒和较低电阻态的晶界区域构成。由此可知,在BaCo0.02ⅡCo0.04ⅢBi0.94O3中添加Ba0.5Bi0.5Fe0.9Sn0.1O3改善了热敏行为但也恶化了电流特征.

简介：15%Ag-addedcubicperovskitesSr0.9La0.1TiO3andRuddlesden-Popper(RP)phasesSr2.7La0.3Ti2O7werefabricatedviahydrothermalsynthesis,coldpressingandhigh-temperaturesintering.Thestructureandthermoelectricpropertieswerealsoinvestigatedforallsamples.TheresultsindicatedthatAgprecipitatedasasecondphase.AgadditionmadeelectricalconductivityandabsoluteSeebeckcoefficientenhanced,asaresult,theZTvalueswereenhancedbothfortwoseries.Comparedwithcubicperovskite,RPphasewassubjectedtosmallerimpactbyAgaddition.ThereasonsforenhancingZTvalueandthedifferentimpactfortwoseriesbyAgadditionwerealsodiscussed.

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简介：利用射频磁控溅射法在玻璃基片上制备Bi／Bi2O3晶格复合热电薄膜，考察了溅射功率对单层Bi薄膜表面粗糙度和热电性能的影响，结果表明，当溅射功率为22W时，薄膜具有最小的表面粗糙度16.3nm，电导率和功率因子分别为2．9×10^4S／m和5．74μV／k^2m，单层Bi薄膜最佳的工作温度为85～105℃。Bi／Bi2O3晶格复合热电薄膜最佳的溅射层数为5层，其电导率和功率因子分别为9．0×10^4S／m和21．0μN／k^2m，分别比单层Bi薄膜提高了2．1倍和2．65倍。

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简介：研究了Na^＋替代Bi^3＋、Sn^4＋替代Nb^5＋对Bi2（Zn1／3Nb2／3）2O7陶瓷烧结特性、显微结构和介电性能的影响。结果表明，替代后样品的烧结温度从1000℃降低到860℃；在-30～130℃样品出现明显的介电弛豫现象；弛豫激活能在0．3eV左右。用缺陷偶极子和晶格畸变对Na-Sn掺杂Bi2（Zn1／3Nb2／3）2O7的介电弛豫现象进行了解释。

简介：Thermoelectric(TE)materialsareakindoffunctionalmaterialswhichcanbeusedtoconvertdirectlyheatenergytoelectricityorreversely.Thethermoelectriceffectsholdgreatpotentialforapplicationinpowergenerationandrefrigeration.Bi2Te3anditsalloysarewellknownasbestTEmaterialscurrentlyavailablenearroomtemperature.Thispaperstudiesrespectivelytheeffectsofsparkplasmasintering(SPS)onelectricperformanceofBi0.5Sb1.5Te3thermoelectricmaterialsthatarepreparedthroughvacuummeltingandballmilling.ThroughX-rayDiffractionandcoldfieldemissionscanningelectricmicroscopes4800,thephaseconstituentandmicrostructureoftheTEmaterialssampleswereanalyzed.ElectricconductivityandpowerfactorcanbeimprovedwiththeriseofSparkPlasmaSinteringtemperature(from300to500℃)andpressure(from30to60MPa),andthedensityandmechanicalstrengthofBi0.5Sb1.5Te3thermoelectricmaterialincrease,too.