Si基稀磁半導體的制備與電磁性質研究.pdf

1、中國科學院合肥物質科學研究院博士學位論文Si基稀磁半導體的制備與電磁性質研究姓名：馬書炳申請學位級別：博士專業(yè)：凝聚態(tài)物理指導教師：孫玉平20070501AbstractAbstractDilutedmagneticsemiconductors(DMSs)，atypeofmaterialtakingadvantageofbothchargeandspindegreeoffreedom，areexpectedtohaveimportant

2、potentialapplications。Inrecentyears，studyonthepreparingandphysicalpropertiesofthesematerialsisgainingattentioniafieldofcondensedmatterphysitsandmaterialsciencesAmongthem，theSibasedDMSshavereceivedmoreattentionsduetoitsco

3、mpatibilitywithconventionalsemiconductormaterialsThusthisdissertationfocusingonsomeSibasedDMSs，systematicallyinvestigatesthepreparationmethodandelectronictransportandmagneticpropertiesofthistypeofmaterialsSO舔tohaveabette

4、runderstandingofthemFirstly，SlightlyMndopedSilxM域O=O，0005，0，01，0015)polycrystallinesamplesarepreparedbyarcmeltingmethodandelectronictransportandmagneticpropertiesofthesamplesarealsostudiedAlldopedsamplesshowferromagnetic

5、orderingbelowabout250KandthetransitiontemperatureTcincreaSesmonotonouslywiththeincreaseofMndopinglevelThereexistsanobviousmetalinsulatortransitionnearthemagnetictransitiontemperaturesInaddition，alldopedsamplesshowanomalo

6、usHalleffectinthelowtemperatureferromagneticregionSecondlysomeM仔dopedsiliconsinglecrystalsSilxMaxG=0017)aregrownusingtheBridgrnanmethodSiliconswithvarioustypesofcarriersareusedaSthematrixmaterialsTheroomtemperatureferrom

7、agnetismcanbeinducedinallsiliconmatrixesbytheMndopingMeanwhiletheferromagneticinteractionissensitivetothetypeofcarrierinthesilicon，whichisrelatedtotheenhancedmagneticinteractionmediatedbyholesEspecially，thetransitiontemp

8、eraturecanreachesto550KfortheMndopedptypesinglecrystalsampleTheobservedresultsareexplainedbasedonthepercolationmechanismduetoboundmagneticpolaronAdditionally，theelectronictransportandmagneticpropertieshavealsobeenstudied

9、inSi卜xMn，C(0≤石≤O1)polycrystallinesamplespreparedwithconventionalsolid。statereactionThemaximumofthedopinglevelcanreachtox01atpresentsituationAllsamplesshowobviousferromagnetismandthetransitiontemperatureTcincreasesfrom205