ZnO材料相變機理的研究.pdf

1、西北大學碩士學位論文ZnO材料相變機理的研究姓名：朱莉申請學位級別：碩士專業(yè)：凝聚態(tài)物理指導教師：姜振益20100623AbstractFirstprinciplescalculationsandtheplanewavemethodarecarriedtostudythestructuralstabilityofwurtziteZnObyoptimizingthe疋何，theSIGMAtheK面d，andthelatticeconsta

2、ntstepbystepTooptimizetheatomicpositionweusescanningmethodstogetapotentialenergysurfaceaboutthelatticeconstantsc／aandaThelowestpointofthepotentialenergysurfacecorrespondstothemoststablestructure，wherethelatticeconstantsr

3、atioc／ais16256Comparingthefivepseudopotential，theUSPPfunctionalandthePW91pseudopotentialwereselectedtothefollowingcalculationsoftheWZZnOBasedontheabovecalculations，westudytheelasticconstants，thebandstructureandthedensity

4、ofstatesetcmaterialproperties，andanalysisanddiscussthembycomparingwiththeresultsofpreviousThestudyofthree—phaserelationshipbetweenthephasetransitionwereourmainworksWefocusonthetransformationfromWZtoZB，becausetherehavebee

5、nalreadyexistedthephasetransitionbarrierthetransitionpressureandthetransformationpathfromWZtSofZnO，atthesametimethephasetransitionbarrierandthetransformationpathfromZBtSofCdSe，ZnS，SiC，InPetcwerestudiedandreported，ftuther

6、moreamesophaseWasdiscoveredbetweenZBandRSThisarticleshowedthetransformationpathfromZBtoWZ，andthephasetransitionbarrierTheenergybarrierwascalculatedforhomogeneoustransformationfordifferentZnOtransformationpathwaysFromallt

7、hetransformationpathways，amostprobablepathwayisproposedwhoseenergybarrier(O19eV／pair)islowerthananyotherpathwayComparedwimtheenergybarrierbetweenwurtziteandrocksalt(015eV／pair)，theenergybarrierinthisworkisnotobviousdiffe

8、rencefromitFurthermore，compared嘶mtheenergybarrierofOaN(026eV／pair)，theenergybarrierinthisworkisobviouslowerthanitTherefore，itispossibletotransferfromzinc—blendetowurtzitewithrespecttotheenergybarrierThisworkaccountsforwh

9、yitisimpossibletotransfomatedirectlybetweenwurtziteandzincblendeinthermodynamicaspectanddynamicalaspectjustbecauseoflackingofphasetransformationdrivingforceKeywords：ZnOmaterial；VASPsoftware；wurtzitestructureproperties；th