雙摻雜CMR薄膜的結(jié)構(gòu)和光電特性研究.pdf

1、西北工業(yè)大學(xué)碩士學(xué)位論文雙摻雜CMR薄膜的結(jié)構(gòu)和光電特性研究姓名：汪世林申請學(xué)位級別：碩士專業(yè)：光學(xué)工程指導(dǎo)教師：宋宙模20030301AbstractPerovskitecrystalsandthinfilmsofLa2／3(CalxSrx)3Mn03withxrangingfromOto1havebeenpreparedwithsolidstatereactionandRFmagnetronsputteringmethod，inve

2、stigatedbyvarioustechniques：XRDanalysis，resistivityinlowtemperaturescope，magnetoresistance，cwlaserandmodulatedlaserpulseinducedresistivitychanging，ereExperimentspheuomenashowthatthepropertiesofthesematerialsarerelatedwit

3、htheCaandSrdoubledopinglevelgreatlyespeciallyinphotoelectfiealcharacteristicsAllsamplesexhiMtphasetransitkm(FM—PM)whentemperatureofthemiSincreascdItiSshowedthatthemaximumofphotoinducedresistivitychangingratio(AR／R州)m“and

4、itsappearingtemperaturerespectivelydecreasesandincreaseswhenthedopinglevelxchangesfrom0to2／3(AR／gom)m“reaches435％whenxis1whichisanexcitingfigureinthisresearchfieldExperimentresultsshowthat(A剮＆幽㈣isstronglydependentonbiasc

5、uzT芎ntandtemperatureandtherelationshipamongthemshowsanonlinearbehaviorWhatismorethereexistsanoptimalbiascurrentandtemperatureconditionforopticalresponseinLa∞Cait3Mn03thinfilmTheresultsofOUrexperimentssuggestthattheremayb

6、eexistacommonmechanisminresistivitytemperaturepropertyCMReffectandphotoinducedeffect：thestateofdownspinegcalrieisinspinordersystemKeywords：CMR，Perovskitestructnre，Doubleexchange，Photoindueedeffect，Electronicspjn，Magnetro