单相多铁性材料_极化和磁性序参量的耦合与调控

2008年第53卷第10期:1098~11351098*,,,210093;*,E-mail:[e-mail]2007-10-26;2008-01-06(:50332020)(:2002CB613303,2006CB921802),.,;,,.,,.,,.,..,,,.,,:()()..,,.,..(ferromagnetics),(),.,,.,(giantmagnetoresistanteffect,GMR),(magnetoelectronics)(spintronics),.,GMR2007,(magneticrandomaccessmemory,MRAM)[1~4]..(ferroelectrics),().(ferroelastics),(),[5].,,(ferroelectricrandomac-cessmemory,FeRAM),[6].,,,.,,,.,1099,,1..1,(2),,.:,;,.,..,,.,.,,.,..,,(),,--..,.,.,[7~18],.Fiebig[18].,.,,,.1[8]2[11],,(),.[8~13].,Fiebig[18],Tokura[8],Cheong[12]Ramesh[13].,2008年5月第53卷第10期1100[11]..,,.,,,.——,..11.1(multiferroicity)(magnetoelectriceffects,ME).,,().1888,Röntgen,..1894,Curie,.,Debye.[14~16].Cr2O3[17],4.13ps/m.,80[18].0001(,)21211......,22ssiiiiijijijijijijijkijkijkijkFEHFPEMHEEHHEHEHHHEEεεµµαβγ=−−−−−−−−GG(1)EH.0(,)1......,2siiijjijjiijkjkijkijFPEHPEHEHHHEεεαβγ∂=−=++∂+++GG(2)0(,)1......,2siiijjijjiijkjiijkjkFMEHMHEHHEEEµµαβγ∂=−=++∂+++GG(3)PsMs,ˆα,.[18].,,./[18~20].[21~24],(3).,.-,90V/(cm·Oe)(1Oe=79.58A/m)[18].,.,,.,,./,.()().().Schmid()(multiferroics)[25].,,.,.,..,.,,.11013CoFe2O4BaTiO3((a)(b))((c)(d))[24]1.2,,BaTiO3Pb(Zr,Ti)O3,(perovskitestructure)[5,6].,,.,.,.,,.,Bd(d0),Ti4+,Ta5+,W6+.d0.,,.,Cr3+,Mn3+,Fe3+,d,.,,d..,,.,,.,4.,,,,.,..,(ABO3B)4BaTiO3()().,Ti,[10]2008年5月第53卷第10期1102(ligand-fieldhybridization).(Ti4+)d,,.,,5(a).,pdtpdtpd(1±gu),u,g.~(−tpd2/∆),∆.,.,,δE222pdpdpd22pd((1))/((1))/2/2()/.Etgutguttgu∆∆∆∆δ≅−+−−+=−(4),~u2~Bu2/2,,B,,.5(b),d,(),,[10,26].d,(),,.d5(a);(b)[10],,.,,.,[10]..1.3,d,.,.,Maxwell,,,().,,,().,.,()pd(virtualhopping).,(exchangeinteraction)..,,.,.,,,,..,,.(ns)2,Bi3+,Pb2+.(ABO3)A,A.Bd1103,,.,..,,,,,.,/;LuFe2O4,..22.1,.,.GdFe3(BO3)4[27],BO3,Fe3+,.Ni3B7O13I[28].,Ni3B7O13I,[28].,Fe3B7O13ClMn3B7O10Cl[29]...Bd0,B3d,.Pb(Fe1/23+Nb1/25+)O3(PFN),Fe3+Nb5+.,PFN,Néel143K,Curie385K[30~32].PFN~65µC/cm2(6(a)[33]),.,.Kimura[34]Ginzburg-Landau,Φ2420422'2',2PPPEMMMHPMβΦΦααβγ=++−++−+(5)PM,γP2M2.,γ,.22,PεΦ∝∂∂TN,.:TN-,TN,δε,Ginzburg-Landau,δε~γM2.[35].PFN6(c),Neel;130~140K,δεM2,6(d),PFN.Mössbauer,6(b).,[35].PFN,AB1−xB′xO3,Pb(Fe1/23+W1/25+)O3[36]Pb(Fe1/23+Ta1/25+)O3[29],PFN.,,//.2.2,(ns)2.,ssp(sp2,sp3).,,s.(lonepairs).Bi3+Pb3+.(ns)2,(ns)1(np)12008年5月第53卷第10期11046(a)PFN;(b)PFN3K;(c)PFN;(d)[33,35]p,,,[37~39].PbTiO3Na0.5Bi0.5TiO3,[37].Bi3+Pb2+ABO3A,B.,,BiFeO3BiMnO32003,.6sBi3+,Fe3+Mn3+.,.BiMnO3,,,,,.BiMnO3[40],TFE~800K,,7(a)(b)[41];TFM~100K[41].BiMnO3(electronlocaliza-tionfunction,ELFs)[39]..8(a)BiMnO3Bi-OMn-O,LaMnO3.,,.,Mn-O,Bi-O,Bi6sBi.,(),,,[37~39].,(8(b)),BiMnO3Bi6s.BiMnO3(),.,,7.9T0.6%,[41].11057BiMnO3X(a)(b)(c)(d),(d);(e)BiMnO3;(f)[41]8(a)BiMnO3LaMnO3Bi-OMn-O;(b)BiMnO3Bi-O[39]2008年5月第53卷第10期1106BiFeO3,.BiFeO3,R3c,a=b=c=5.633Åα=β=γ=59.4°[42~44],9(a).,,Bi[111],[111],[111],TC~1103K[43].,100µC/cm2.,BiFe,,[001]3.5µC/cm2([111]6.1µC/cm2)[44]..,60µC/cm2,9(b)[45].,,(rapidliquid-phasesintering),,[46].,Bi,BiFe,,[47~49].BiFeO3[50].,.(~60µC/cm2),,[51].BiFeO3,,TN~643K.,9(a)BiFeO3R3c[56].[111],[111],[111].[100],BiFeO3.(b)BiFeO3.~60µC/cm2,~12kV/cm.(c)BiFeO3[43,45]1107[43],,()~62nm,9(c).,BiFeO3.,,,.,[51].BiFeO3.10,40nm4nm,[52].,BiFeO3[53].1040nm4nmBiFeO35nm,14nm,25nm,40nm[51]BiMnO3,BiFeO3..(in-planepiezo-forcemicroscopy,IPPFM)[54,55],X(X-rayphotoemissionelectronmi-croscopy,PEEM).BiFeO3[111],z,,9(a),[111].,Ramesh[56](001)BiFeO3,,11.11(a)(b)X,(c)(d)PFM,(e)PFM,[56],PEEM..,,Bi.,AurivilliusBi4+nTi3FenO12+3n[57].,BiFeO3,FeCr(superexchangeinter-action)[58,59],Bi2FeCrO6[60].FeCr,Fe/Cr,[61].PbPbVO3[62].,2008年5月第53卷第10期1108,,.2.3,.,,.(geometricferroelectricity).RMnO3(R=Ho-LuY).BMn,A,.YMnO3,TC~950K,TN~77K[63,64].YMnO3LaMnO3,.YMnO312(a),MnO5(OP),MnO5Y..LaMnO3MnMnO6;YMnO3MnMnO5,(5-foldcoordi-nation).,YLa12,7.,LaMnO3Mndt2geg,YMnO3Mnd(e1ge2g)ag.Mn3+d,.,YMnO3MnJahn-Teller(12(b)).2060,YMnO3P63cm,Mn[63].Mn(OT),[63].,MnMnO5,[65].,Mn,[65].,P63/mmcab,P63cmc,12(a)1312(a)YMnO3.,.(b)YMnO3Mn3+[65].,.,MnO5,c,O(OT)Y-OP;,Y,OT,12(a)..2.8ÅY-OP~2.3Å,~3.4Å,,13[65].,X(X-rayabsorptionspectroscopy,XAS),Y4dO2p,YOBorn[66],YMnO3Y-O.110913(a)(b)YMnO3Y,MnO5.,.,Å.[65],YMnO3Y-O,Mn-O,A..,,VanAkenRMnO3.,..,MnO5,[10].,RMnO3R-Op,..,Fiebig.180°:(+P,+l),(+P,−l),(−P,+l),(−P,−l),±P±l,“+”“−”.,(domainwall)[67].,,PM.HoMnO3[68,69],TC~875K,Mn3+TN~75K.P63cm,c5.6µC/cm2[68].,HoMnO3Mn3+,fHo3+THo~4.6K.HoMnO314,HoMnO36cMn3+(3d3)2a4bHo3+(4f10).Mn3+ab(xy),(spinfrustration).Ho3+z(c)Ising.,.,/,,.HoMnO3,Mn3+[68].,HoMnO3YMnO3Ho3+.,Ho3+,14.,Ho3+-Mn3+[68],.[69,70].,,.,Al2O3,TbMnO3,TbMnO3[71].,TbMnO3(TbMnO3,).2008年5月第53卷第10期111014HoMnO3[68]2.4,,,/,.,/..,(),.,/.1.2,d.(),,.,PEr−r,t−t.,,MH,[11]..,PM.+P2,(4)−P2M2,.2.12.2,PFNBiMnO3.,M,,.PM∂M.P,.,,[()()],∝⋅∂−∂⋅PMMMM(6),M.,.[72],J0,.J′0,,:Sn=S[e1cosQxn+e2sinQxn](15(a)),e1e2,e3,Qcos(Q/2)=−J′/(4J),,.,,,.111115(a)(b);(c)DMLa2CuO4RMnO3[10],.,,..(),.,,.Dzyaloshinskii-Moriya(DM)[73,74].,Dn,n+1⋅Sn×Sn+1,Dn,n+1Dzyaloshinskii-Moriya,Snn[75,76].-[75],-.DM.La2CuO4,DMCu-O,15(c)[77].,,DMDn,n+1x×rn,n+1,rn,n+1nn+1,x,15(c).DMx.La2CuO4,,DM,;,Sn×Sn+1,DM,15(c),.,,Qe3,P~Q×e3.(7),SnSn+1(spinprecession)[74]..()..,|J′/J|1/4,15(a)[78].LiCu2O2,16(