a
CSNSM,UniversitéParis-Sud,CNRS-IN2P3,Bat.108,91405Orsay,France
DepartmentofMaterialsScienceandEngineering,UniversityofTennessee,Knoxville,TN37996,USAc
HelsinkiInstituteofPhysicsandDepartmentofPhysics,UniversityofHelsinki,P.O.Box43,HelsinkiFI-00014,Finlandd
MaterialsScienceandTechnologyDivision,OakRidgeNationalLaboratory,OakRidge,TN37831,USAe
CIMAP,CEA–CNRS–ENSICAEN-UniversityofCaen,14070CaenCedex5,Francef
InstitutPPRIME,ENSMA–CNRS-UniversityofPoitiers,BP30179,86962Futuroscope-ChasseneuilCedex,France
b
articleinfoabstract
3C-SiCsinglecrystalshavebeeninitiallyirradiatedinthenuclearenergylossregimewith100keVFeionsto?uencesrangingfrom4?1013to4?1014cmà2(i.e.0.07–0.7dpa).RBS/CmeasurementsindicatethatSiCrapidlybecomesamorphous(at$0.4dpa).TwodamagedSiCcrystalsexhibitingadifferentdefectivestructurehavebeensubsequentlyirradiatedintheelectronicenergylossregimewith870MeVswiftheavy(Pb)ions(SHIs)uptoa?uenceof4?1013cmà2.InitiallyfullyamorphousSiClayersshowedadecreaseinsizeafterSHIirradiationwitharecrystallizationoccurringattheamorphous–crystallineinterface.Onthecontrary,partiallyamorphouscrystalsforwhichonsetofamorphizationjustinitiatedatthedamagepeakrecoveredovertheentiredamagethickness.Variationofamorphousthicknessordis-orderlevelhasbeenmonitoredasafunctionofPbion?uence,whichallowedderivingrecrystallizationkinetics.Datahavebeen?ttedwiththedirect-impactmodelandrecrystallizationcross-sectionsandthresholdvaluesforrecoveryhavebeendeterminedforbothtypesofinitiallydefectivestructures.Dif-ferencesarequalitativelydiscussedintermsofnatureanddensityofirradiationdefects.AllexperimentaltrendshavebeensuccessfullyreproducedbymoleculardynamicssimulationsthatmimickedthermalspikesinducedbySHIs.
ó2014ElsevierB.V.Allrightsreserved.
Articlehistory:
Received28June2013
Receivedinrevisedform1October2013Accepted25October2013
Availableonline3February2014Keywords:IrradiationSiC
SwiftheavyionRecrystallization
1.Introduction
Overthelastdecades,siliconcarbide(SiC)hasbeenattractinganincreasinginterestowingtomanyoutstandingphysicalandchemicalpropertiesthatmakeitaprominentcandidatematerialformanyapplications,forinstanceinextremeenvironmentssuchasstructuralcomponentsin?ssionandfusionreactors[1]orformicroelectronicsdevices[2].AmorerecentuseofSiCisforthedevelopmentofDilutedMagneticSemiconductormaterials(DMS)forspintronicsapplications[3],wheremagneticdopantsmustbeintroducedinsemiconductorhostmatrices.Inthisframe-work,SiC,whichisawidebandgapsemiconductorwithexcellenttransportproperties,hasbeenshowntobeapromisingcandidatewhendopedwithtransitionmetals[4,5].Foralltheseapplications,SiCwillbesubjectedtoionirradiation,eitherduringitslifetime(forinstanceinanuclearreactor)orduringitssynthesis(namelyduringtheionbeamdopingprocess).Therefore,acomprehensiveCorrespondingauthor.Tel.:+33169153595.
E-mailaddress:aurelien.debelle@u-psud.fr(A.Debelle).
0168-583X/$-seefrontmatteró2014ElsevierB.V.Allrightsreserved.http://dx.doi.org/10.1016/j.nimb.2013.10.080
understandingofitsbehaviorunderionirradiationappearsasamajorfundamentalissue.Thisstatementisstrengthenedbythefactthatinthismaterialmorethaninothers,irradiationdefectsexhibitasubtlebehaviorwheredefectcreationandannihilationratesintimatelydependontheirradiationconditionsandespe-ciallyontheenergylossregime.
StudiesofSiCirradiatedinthenuclearenergylossregimeunambiguouslyestablishedthatthismaterialisreadily–i.e.atafractionofdisplacementperatom,dpa–amorphizedbyballisticcollisiondisplacements(seee.g.[6,7]),andthattheheaviertheion(atequivalentenergy),thefasteristheamorphizationprocess[8].Thislatterstatementhasbeenexplainedbymoleculardynam-ics(MD)simulationsthatshowedthatheavierionscreatedensercollisioncascadesandtheremainingdefectsarefoundtobelargerandcanbeconsideredassmallamorphouspockets[9].Ontheotherhand,irradiationofSiCwithswiftheavyions(SHIs)hasclearlyproventobeamuchlessdamagingprocess,sinceitonlyleadstosomeproductionofpointdefects[10,11].Moreinterest-ingly,in6H-SiCirradiationdamagedwithlowenergyions,ithasbeenobservedthatsubsequentSHIirradiationintheGeVenergy
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