Ⅰ-型鍺基籠式化合物的制備及熱電性能.pdf

1、武漢理工大學(xué)碩士學(xué)位論文Ⅰ型鍺基籠式化合物的制備及熱電性能姓名：李鵬申請學(xué)位級別：碩士專業(yè)：材料學(xué)指導(dǎo)教師：唐新峰20080401武漢理工大學(xué)碩士學(xué)位論文ABSTRACTAspotentialhighperformancethermoelectricmaterials，clathratecompoundswith‘‘phononglass，electroncrystal”(PGEC)characteristichaveattracted

2、greatattentionduringthelastdecadeRencentlythestudieswithrespecttoclathratesaremainlyfocusedontheorycalculations，structureinformationandlowtemperaturethermoelectricpropertiesHoweverwecouldfindlittleinformationinliterature

3、sonthemicrostmctureanalysisandhi【ghtemperaturethermoelectricpropertiesInthisthesis，themicrostructttreandthermoelectrictransportpropertiesoftheBasGal6Ge30andBasSb2Gal4Ge30compoundshavebeeninvestigated，thestructureandtherm

4、oelectricpropertiesofthetypeIYbxBasxGal6Ge30clathratesalsobeeninvestigatedandthemainobtainedresultsasfollowsBasGal6Ge30andBasSb2Gal4Ge30bulkmaterialswithfinenanostructurehavebeenpreparedbycombiningmeltspinningtechniquewi

5、廿lsparkplasmasintering(SPS)XRDpatternsshowsthatthesinglephaseoftypeIclathrateobtainedaftermeltspinningandSPSEDSrevealthatalialefluctuationofcompositionhappenedduringthecourseofmeltspinningandSPSFESEManalysisrevealthatthe

6、meltspinningtechniquesbringlotsofmicronstructureandnanostructureintothebulkmaterials，andthegarinsizereduceswimtheincreasesofcoolingrateFortheBasGal6Ge30bulkmaterials，compared謝tllthesamplepreparedbymeltingmethodtheelectri

7、calconductivityreducedslightlyandtheSeebeckcoefficientincreasesgreatlyintherangeofthetestingtemperatureThelatticethermalconductivitydecreaseremarkablyduetothegrainboundaryintensifythephononscatteringinthelatticeThesample

8、hasthegreatestZTvaluewhichpreparedbymeltspinningwiththeroller’Slinearrateof40m／s，anditsmaximalZTvaluereaches096atabout950KFortheBa8Sb2Gal4Ge30bulkmaterials，comparedwiththesamplepreparedbymeltingmethod，theelectricalconduc

9、tivityincreasesgreatlyandthelatticethermalconductivitydecreasessignificantlyintherangeofthetestingtemperatureThesamplehasthegreatestZTvaluewhichpreparedbymeltspinningwiththeroller’Slinearrateof40m／s，anditsmaximalZTvalueⅡ