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1、AtomsinmagneticfieldAbstractInmagneticfield,aelectronwhichhasspinandresolvesthenucleusisactedbymagnetictorque.Thatresultsinthemagneticenergyandalsothechangeofangularmomentum-Theelectronspinresonanceisasituationoftheoverturnofangularmomentum.Zeemaneffecta
2、ndPaschervBackeffectaretheenergyshiftandsplittingcausedbymagneticfield.Thethreeofthemisancomprehensivepicturetodescribeanatominmagneticfield.1ElectronSpinResonance
3、t
4、Theelectronspinresonaneeisactuallyamethodtostudythebehaviorofelectronandisaphenomenontha
5、twhenanewoscillatorymagneticfieldwithacertainfrequencyisaddedtoastaticonewouldcausetheelectronwhichwasprocessingaroundtheoriginalfieldturnoveritsspindirection.Inpracticaluse,onedirectionforthehorizontaioscillatoryfieldissufficient,sayingthex-direction.Ho
6、wever,toillustrateclearly,thehorizontaifieldhereisgiveninthex-yplane.Thephase-differencebetweenandissetas71/2andthetwoAycomponentshavesameamplititudesothatB,isacircularfield.Ifweignorethehorizontalfieldfirst,themagneticmomentwouldbeprecessingalongthestat
7、icfieldonBo.Theprecessionangularvelocityisco=-—wheregistheLandeg-factor,h“bistheBohrmagneticmoment.Now,iftheperpendicularmagneticfieldBxhastheverysameangularfrequency.ThenthetorquegeneratedbyitwouldbelikeawrenchprecessingaroundB()withthe“synchronously,as
8、showedinFig1.1.Afterashorttime/zzsdirectionwouldbechangedalittleandrevolvingonanothercircle.Finally,thedirectionofitwillbeturnedover.Besides,fromtheviewofenergyconservation,thechangeofmagneticmoment'senergyisAE=tico=2-msgiLiBB^,justenoughforanelectrontof
9、lip.Nevertheless,wedidn'tusesomepeculiarpropertyofspin,whichmeansit'salsoapplicablefororbitalmagneticmoment,andwhenthatisturnedintoconsideration,/n.sinplaceof/ns.ZeemaneffectTheZeemaneffectistheeffectofsplittingaspectrallineintoseveralcomponentsinthepre
10、seneeofastaticandweakmagneticfield.
11、2)Thecalculationofcanbeobtainbothfromthevectormodelorthecalculationofoperator.Although,it'squitevisualtousetheformerone,itcanalsobringsomeproblemsandmakesomeconceptsvagueandunclear.Forex