简介:Geepilayersofdifferentthicknessesaregrownbymolecular-beamepitaxywithSbasasurfactantonSI(100)substrates,X-raydiffractionillustratesthattheseGethinfilmsarepartiallystrained.andthestrainsdecreasegraduallywithincreasingepilayerthickness,RamanspectrarevealadownwardshiftoftheGe-Gemodepeakastheepilayerthicknessincreases.Intheregionsofhighstrain,therelationshipbetweentheRamanshiftofthismodeandthestraininthepartiallyrelaxedsamplesisconsiderablydifferentfromthelinearrelationshipreportedbefore,whichismainlyattributedtothespatialconfinementeffectofphononsinananocrystal.
简介:通过原位下的高压同步辐射X光衍射技术,对具有钙钛矿结构的La0.4Bi0.1Ca0.5MnO3中存在的Jahn-Teller畸变,进行了研究。实验表明在压力的作用下,样品中的畸变有所减小,超于理想的立方结构,并且在1.4GPa左右存在一个过渡相。
简介:GaInP/GaAs/Getriple-junctionsolarcellswereirradiatedwith50keVand100keVprotonsatfluencesof5×1010cm-2,1×1011cm-2,1×1012cm-2,and1×1013cm-2.Theirperformancedegradationisanalyzedusingcurrent-voltagecharacteristicsandspectralresponsemeasurements,andthenthechangesinIsc,Voc,Pmaxandthespectralresponseofthecellsareobservedasfunctionsofprotonirradiationfluenceandenergy.Theresultsshowthatthespectralresponseofthetopcelldegradesmoresignificantlythanthatofthemiddlecell,and100keVproton-induceddegradationratesofIsc,VocandPmaxarelargercomparedwith50keVprotonirradiation.
简介:用不同束斑的SRXRF微不,对1个土壤成分分析标准物质和1个岩石成分分析标准物质进行了多点测量,通过样品缓慢移动,在2个土壤成分分析标准物质和2个岩名成分分析标准物质上分别选取2—3个高度为5mm的小区,进行扫描测量。结果表明,不论SRXRF微束束斑大小,标准参考物的均匀性都不是很好;在目前没有微束分析用的标准参考物的情况下,采用多区域扫描测量的方法,现有的标准参考物作质量控制是可行的。