三明治結(jié)構(gòu)薄膜巨磁阻抗效應(yīng)的電磁理論研究.pdf

1、華東師范大學(xué)碩士學(xué)位論文三明治結(jié)構(gòu)薄膜巨磁阻抗效應(yīng)的電磁理論研究姓名：黃燦星申請(qǐng)學(xué)位級(jí)別：碩士專業(yè)：凝聚態(tài)物理學(xué)指導(dǎo)教師：馬學(xué)鳴20050501ABSTRACTAmodelofGiantMagneto—Impedance(GMI)effectforsandwichstructuredfilmsconsistingoftwosoftmagneticlayersandallinnernonmagneticmetallayerwaspropo

2、sed，theGMIeffectwasinvestigatedtheoreticallyThemaininnovativeresultswereasfollows：1Amodelofsandwich—structuredfihnwasproposedbasedontheprincipleoffieldsuperposition，theMaxwellequationswereresolvedundercertainboundarycond

3、itionsandtheelectroIna￡neticfieldinthesandwich—structuredfilmwasderivedFromtherelationbetweentheenergytransferandtheimpedanceforthefilm，theexpressionoftheACimpedancewasderived，thewellacceptedimpedanceexpressionformonofil

4、mcouldbededucedfromtheexpressionforthesandwichSIrLIcturedfilm2Consideringthemotionofthemagnetizationundertheexternalmagneticfield，weusedLandau—LifshitzequationtodescribethemotionandwegottherelationbetweentheACmagnetizati

5、onandACmagneticfield，SOdidthemagneticpermeabilitytenser，thenweobtainedtheeffectiveACtransversemagneticpermeability3Utilizingtheexpressionoftheimpedanceandmagneticpermeability，WecalculatedthedependenceoftheGMIeffectsonvar

6、iousparametersofthesandwichstructuredfilmsTheresultsofthesimulationshowedthattheGMIratioforasandwichstructuredfilmsandwichinghighconductivemetallayerwasseveraltimeslagerthanthatforamonofilm，andthemaxinarmimpedancechanger

7、atiooccurredatthefrequencyofabout10MHzwhichwaslowerthanthatofsinglelayerfilm，Iftheelectricconductivityoftheinneriayerwasverysmall(suchasmetalTi)，aSthoughitwasasandwichstructuredfilmitSGMIeffeCtwasweaktheresultwaslnagreem

8、entwithexpetlimentalresultsThecalculateddependencesofGMIeffects011otherparametersweresimilartOtheexperimentalresults；theseresultsverifiedthetheoretica】model4TheGMIeffectsforsandwichstructuredfilmandmonofilmwerediscussedf

9、ronlthecalculatedelec【romagneticfielddistribution，theinteractionbetweentheinnellmetallayerandtheoutermagneticlayerwasinvestigatedandskineffectinmagneticlayerwasstilltheinlportantfactoroflargeGM[effectforsandwichH【I_uctur