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Thecubiccrystalstructureofzirconiumtungstateexhibitsisotropicnegativethermalexpansion(NTE).Asaresult,ultrafinezirconiumtungstatemightfinduseinapplicationswhichrequiretailoredthermalexpansionproperties.Inthiswork,thepreparationofultrafineZrW2O8powderswithdifferentparticlesizerawoxidesmaterialsbystep-solid-statereactionandthenegativethermalpropertyoftheresultedproduceswerestudied.Decompositionbehavioroftherawmixturewasstudiedusingdifferentialscanningcalorimeter(DSC),thestructuresofZrO2,WO3andcubicZrW2O8werecharacterizedbyPowderX-raydiffraction(XRD),andthemorphologyoftheresultingZrO2,WO3andZrW2O8werestudiedbyscanningelectronmicroscope(SEM).TheresultsshowthattheNTEpropertyandparticlesizeoftheresultedZrW2O8isdependedontheparticlesizeofrawoxidesmaterials.UltrafinecubicZrW2O8exhibitingbetterNTEpropertycouldonlybyobtainedusingnanoZrO2andWO3asstartingmaterials.Inthetemperaturerangefrom20to600℃,thethermalcoefficientofultrafinecubicZrW2O8is－7.6410-6K-1,whichbiggerthanthethermalcoefficientZrW2O8(－6.8210-6K-1)preparedbymicroZrO2andWO3.ThismethodcanbeindustrializedtoprepareultrafinecubicZrW2O8whichcanbeutilizedinmorefields. |
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