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:在这份报纸,有石墨(C)或碳nanotubes(CNT)的增加的SmCo6.9Hf0.1当演员组合金和带子被融化的弧和融化旋转分别地准备。补充说结构和磁性SmCo6.9Hf0.1上的碳借助于X光检查衍射(XRD)被调查的效果,扫描电子显微镜学(SEM),传播电子显微镜学(TEM),磁性的力量显微镜学(MFM)和颤动的样品磁强计(VSM)。尽管他们的水晶结构作为一样的Sm被描绘,微观结构和SmCo6.9Hf0.1带子的磁性的结构由于C或CNT的介绍显然被改变,这被发现尽管他们的水晶结构作为一样的Sm被描绘(公司,Hf)7单个阶段,不管碳被增加。作为结果,包含碳的带子的磁性在某个度被提高。这被认为与精制equiaxed谷物,小领域尺寸和C或CNTs富有的区域的卡住的效果有关。SmCo6.9Hf0.1(CNT)的磁性0.05条带子到达了Hc=12.5kOe,Mr=57.0emu/g和Mr/M2T=0.788。
简介:LuminescencelifetimeofCe(Ⅲ)forCe0.9RE0.1P5O14,whereREdenotesrareearthionsotherthanCe(Ⅲ),wasmeasuredbymeansofthetime-correlatedsinglephotoncountingtechnique.Ithasbeenfoundthatthelifetimedataarecapableofelucidatingtheenhancementorquenchingofcerium(Ⅲ)luminescencebyalienREions(otherthanCe)indoublydopedceriumpentaphosphatecrystal.
简介:ThemagneticpropertiesandthephasestructureofTb1-xPrxFe1.96(x=0,0.1,...,0.7)werestudied.ItisfoundthatthesaturationmagnetizationoneasyaxisisdecreasedwithincreaseofPrcon-tent,from77.24Am^2·kg^-1forx=0,reducestominimumvalueof11.84Am^2·kg^-1forx=0.5,andreturnesto37.14Am^2·kg^-1forx=0.7.Thenon-cu-bicphasesappearbeyondx=0.2andthematrixchangesfrom1:2phaseforx=0to1:3phaseforx=0.4,atlastto2:17phaseforx=0.7.Thecom-poundsstructurewouldturnmorecomplexasthePrcontentincreases.
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.
简介:15%Ag-addedcubicperovskitesSr0.9La0.1TiO3andRuddlesden-Popper(RP)phasesSr2.7La0.3Ti2O7werefabricatedviahydrothermalsynthesis,coldpressingandhigh-temperaturesintering.Thestructureandthermoelectricpropertieswerealsoinvestigatedforallsamples.TheresultsindicatedthatAgprecipitatedasasecondphase.AgadditionmadeelectricalconductivityandabsoluteSeebeckcoefficientenhanced,asaresult,theZTvalueswereenhancedbothfortwoseries.Comparedwithcubicperovskite,RPphasewassubjectedtosmallerimpactbyAgaddition.ThereasonsforenhancingZTvalueandthedifferentimpactfortwoseriesbyAgadditionwerealsodiscussed.
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:目前国内外锂离子电池正极材料规模化的有钴酸锂、镍酸锂、锰酸锂、磷酸铁锂,锰系材料资源丰富、价格低廉、对环境无污染,锰酸锂具有尖晶石和层状两种结构,而层状LiMnO2具有无毒、安全、理论容量高等优点,已成为目前研究的热点。以专用的MnO2与电池级Li2CO3为原料,采用高温固相法,对材料进行合成,得到了合成层状锰酸锂的最佳条件为:原料中锂锰摩尔比为1.03∶1,氩气保护气氛下,合成温度为800℃,合成反应的恒温时间为10h。材料在0.1C的初始充电比容量为235.6mAh/g,放电比容量可达148.4mAh/g,0.1C下放电时,材料循环20次时,材料的放电比容量约为160mAh/g;当材料在0.2C放电时,放电比容量120mAh/g以上。但纯相的LiMnO2材料高倍率充放电性能较差,目前距离商业化还有一定的距离。