β-FeSi-,2-的形成及剩余Fe的存在形式.pdf

1、中國科學(xué)技術(shù)大學(xué)碩士學(xué)位論文βFeSi的形成及剩余Fe的存在形式姓名：朱陳輝申請(qǐng)學(xué)位級(jí)別：碩士專業(yè)：凝聚態(tài)物理指導(dǎo)教師：李玉芝2002.5.1!墮型墊塵蘭絲!：絲苧一j些墅!墜Abstract13FeSi2hasastrongapplicationbackgroundforitsdirectenergygap087eVTherearemanywaystoproduce13FeSi2WeuseFe30SiT0powdertoproduce

2、J3FeSi2byballmillingfor20，40，50，60and80hoursTheX—raydiffractionpaaem，Mossbauerspectra，RamanscatteringspectraandHRTEM／EDAXaleusedtoinvestigatetheasmilledsamplesTheresultsshowthat／3FeSi2isproducedintheFe30SiT0powdersampleb

3、ylowenergyballmillingfQ=200revmin”，R=105cm)，anditsproportionincreasesstepbystepasthemillingtimeincreasesuntilthemillingtimereached60h，afterthatthissolidreactionreachessaturationWithinthefinalproducts，therealeover90％13FeS

4、i2andalittleFeandSiremnantsTogetridoftheremnantFefromas—milledsamples，weuseHCItotreatthesampleButalittleFestillremainsWhydoesoFealwaysexistsInwhatstyleitexistsBasedontheexperiments，weconcludethatinasmilledsamplesQFeexist

5、sintwostyles：oneisinpowderandthesecondisenvelopedby13FeSi2Whenusinghydrochloricacid(HCI)tOtreattheasmilledsample，thefirstpartofo—FeisremovedbutthesecondpartofaFestillremainsInaddition，whenstudyingtherelationshipbetweenth

6、eproportionofthesecondpartQ—Feandthemilltime，wefoundthattheproportionreachesitsmaxwhenballmilling50hHencewesupposetherealetworeactionsdudngballmillingprocess：Oneisthesurfacereactiontoproduce13FeSi2betweenFeandSipowerbydr

7、ivingforceofballmilling，atthesanletimesomenFeissurroundedby13FeSi2AnotherprocessisthatSipowerdiffusesthrough3FeSi2layerandreactswithFeinside，butSicannotdiffuseinto13FeSi2layerverydeepItcannotexhaustallFeinside，SOtheaFest

8、illexistsalthoughveryfewThetwoprocessescoexistduringtheballmillingprocedureButthefirstprocessplaysthemainrolebefore50hballmilling，after50hthesecondprocessinfluencestheproportionofaFemainlyThiscompetitionmakestheproportio