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《Field-induced hexagonal to square transition of the vortex lattice in overdoped La{1.8}Sr{0》由会员上传分享，免费在线阅读，更多相关内容在行业资料-天天文库。
1、Field-inducedhexagonaltosquaretransitionofthevortexlatticeinoverdopedLa1.8Sr0.2CuO411222R.Gilardi,J.Mesot,A.J.Drew,U.Divakar,S.L.Lee,N.H.3455Andersen,J.Kohlbrecher,N.Momono,M.Oda(1)LaboratoryforNeutronScattering;ETHZurichandPSIVilligen;CH-5232VilligenPSI;Switzerland(2)SchoolofPhysicsandAstr
2、onomy;UniversityofSt.AndrewsNorthHaugh;StAndrewsKY169SS;UnitedKingdom(3)MaterialResearchDepartment;RisoNationalLaboratory;4000Roskilde;Denmark(4)SpallationNeutronSourceDivision;PSIVilligen;CH-5232Villigen;Switzerland(5)DepartementofPhysics;HokkaidoUniversity;Sapporo060-0810;JapanABSTRACTWer
3、eportonasmallangleneutronscatteringstudyofthevortexlatticeinoverdopedLa2-xSrxCuO4(x=0.2)uptohighmagneticfields(9.5Tesla)appliedperpendiculartotheCuO2planes.Atlowmagneticfieldsweobserveacrossoverfromhexagonaltosquarecoordinationofthevortexlattice.Thisfield-inducedtransitionconfirmstheresults
4、obtainedinslightlyoverdopedLa2-xSrxCuO4(x=0.17).High-temperaturesuperconductors(HTSC)SANS-IdiffractometeratthePaulScherrerrenewedtheinterestinthestudyofvortexInstitute,Switzerland.ThehighqualitymatterinTyp-IIsuperconductors[1,2].LSCOsinglecrystal(Tc=31K,m=1270mg)Surprisingly,almostnoinforma
5、tionexistswasmountedinacryostatinamagneticaboutthemicroscopicobservationofavortexfieldupto9.5Tesla(appliedparalleltothelattice(VL)inLa2-xSrxCuO4(LSCO),aincidentbeam)withthec-axisorientedcompoundbelongingtothefamilyofthefirstalongthefielddirection.HTSCtobediscovered.UsingsmallangleFig.1shows
6、SANSdiffractionpatternsneutronscattering(SANS),wehaverecentlyobtainedatT=1.5Kafterfield-coolinginreportedthefirstdirectevidenceofawellB=0.05T,0.4T,5Tand9.5T.AorderedVLinslightlyoverdopedLSCObackgroundmeasuredaboveTchasbeen(x=0.17)andtheobservationofafield-subtractedinordertoremovethelargein
7、ducedtransitionfromahexagonaltoasignalarisingfromcrystaldefectscattering.squareVLorientedalongtheCu-ObondsAtverylowfields(B=0.05T)oneobserves[3,4].TheexistenceofanintrinsicsquareVLaring-likedistributionofintensity,whichishadneverbeenobservedinHTSC,andisr
