简介：Heterogeneousprecipitationmethodwasusedtopreparedsurfacecoatingonself-madeBaMgAl10O17:Euphosphor.Resultsillustratethatthecoatingfilmcanbesilicondioxideinamorphousstatewith50nminthickness.Photoluminescenceresultsindicatethatthecoatinglayerpresentsanobservableimprovedeffectontheenhancementofthermalstability.Whenbakedat600℃for1h,theluminanceofcoatedBAMkeepsat92%higherthanthatofuncoatedBAMby23%.ThisprotectiveeffectcanbeattributedtothehighcompactdegreeanduniformityofthisamorphousSiO2coatingfilmwhichisservedasadiffusionblocklayertoinbreakoxygenatom,thusreleasestheoxidationextentofEu2+effectively.

简介：钕铁硼系磁体的推出,使Sm_2Co_(17)磁体的市场规模大大减少。最近日本信越化学工业公司的研究表明,该磁体可以暴露于200℃以上的高温下,还可在氢气等特殊环境下使用。钕系列磁体用于大功率马达的情况下,由于周围环境及焦耳热使温度升高,产生的

简介：利用粉末冶金方法研制了Sm(CobalFe0.24Cu0.08Zr0.027)7.0,Sm(CpbalFe0.27Cu0.05Zr0.027)7.0,Sm(CobalFe0.26Cu0.05Zr0.026)7.03种高温永磁,并对其磁性能、温度稳定性和显微结构进行了分析.结果表明:样品Sm(CobalFe0.27Cu0.05Zr0.027)7.0具有最高的内禀矫顽力(2165.6kA·m-1)和最大磁能积(212.0kA·m-3);3种磁体的温度系数都较低,最高使用温度均在400℃以上,大大高于一般商用磁体;增加Sm,Co,Cu的含量和减少Fe的含量可以提高材料的温度稳定性.X射线分析表明,合金中含有Sm2(Co,Fe)17主相,Sm(Co,Cu)5相,含Zr化合物等.Sm(Co,Cu)5相、单质Zr、晶粒边界等钉扎畴壁,使合金具有较高的矫顽力.

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简介：La1.5Mg17Ni0.5hydrogenstoragematerialswerepreparedbyhydridingcombustionsynthesis(HCS)andmechanicalalloying(MA)methodrespectively.TheexperimentalresultsshowthatthehydrogenabsorptionpropertiesofLa1.5Mg17Nio.5preparedbyMAarebetterthanthatbyHCS.La1.5Mg17Nio.5preparedbyMAcanabsorb6.73mass%hydrogenat523Kwithin1min,and4.92mass%hydrogenat423K.TheimprovementofhydridingpropertiesofLa1.5Mg17Ni0.5alloypreparedbyMAcanbeascribedtotheformationofnano-crystallineanddefectsduringthemechanicalalloying.

简介：SinglephaseofBa1-xMgAl10O17:xEu2+(0.02≤x≤0.14)phosphorswasfirstsuccessfullypreparedbyco-precipitationinaqueousmediumwitha'reversestrike'method,usingoxalicacidandammoniatogetherasprecipitants.Completelycrystallizedphosphorswereobtainedat1300℃,whichis300℃lowerthanthetemperatureofsolid-statereaction.TheirphotoluminescencewasinvestigatedunderUVandVUVregion,respectively.TheemissionspectraofBa1-xMgAl10O17:xEu2+samplesexcitedby254or147nmshowedacharacteristicwidebandwiththepeakcentredatabout450～454nm.Optimumemissionintensityreachedatx=0.1andthenconcentrationquenchingoccurred.Thesynthesizedphosphorshows10%higheremissionintensitythanthatpreparedbysolid-statereaction.

简介：ThephotocatalystsK4Nb6017andK4Nb6017dopedwithFe^3+andCr^3+werepreparedbysolidstatereactionandwerecharacterizedbypowderx-raydiffraction,UV-visdiffusivereflectanceandscanningelectronmicroscopy.ThephotocatalyticactivityofK4Nb6O17andK4Nb6O17dopedwithFe^3+,Cr^3+wereinvestigatedwithmethanolaselectrondonorandPtaspromotercatalystunder+400nmUVirradiation.Thedifferenceofphotocatalyticactivitybetweenthemwasalsodiscussed.TheindividualrateofhydrogenevolutionfortheK4Nb6O17,Fe-K4Nb6O17andCr-K4Nb6O17asphotocatalystsare5.35,5.00,6.25mmol·L^-1.h^-1respectively.