资源描述:
《高娟娟论文4 - 副本》由会员上传分享,免费在线阅读,更多相关内容在学术论文-天天文库。
1、山西师范大学本科毕业论文过渡金属Co团簇的实验与理论研究进展姓名高娟娟院系化材学院专业化学与材料科学班级0901学号0953010145指导教师吕瑾答辩日期成绩19过渡金属Co团簇的实验与理论研究进展内容摘要过渡金属团簇因为具有高磁性和高反应活性,在开发新磁性材料和新催化剂领域具有广阔的应用前景。实验上采用Stern-Gerlach技术【1-4】对Con团簇的平均磁距进行检测,从而对团簇的磁性特征进一步展开研究,研究表明温度、团簇的尺寸大小以及磁场强度这些因素都对Con团簇的磁性有重要的影响,并且研究表明团簇的磁性与温度以及磁场强度成正相关。而磁性随着团簇的尺寸大小的增
2、大先减小后不变,最后稳定到体材料的磁矩。理论上先预测Con团簇的基态结构,然后再对团簇的磁性进行探讨,研究表明影响Con团簇的磁性的主要因素有对称性、平均配位数、平均键长。平均键长和对称性与磁性呈正相关,而平均配位数的大小却与磁性呈负相关。实验和理论都证明在一定数目的原子范围内团簇的磁性远大于体材料的磁性,而超过一定原子数目以后,团簇的磁性逐渐向体材料靠近最后与体材料的磁性相同,这时团簇转变为体材料,发生了质的变化。【关键词】: 钴团簇Stern-Gerlach技术几何结构电子结构磁性19Experimentalandtheoreticalstudiesoftransi
3、tionmetalCoclusterAbstractTransitionmetalclustersbecauseofthehighmagneticpropertiesandhighreactivity,inthedevelopmentofnewmagneticmaterialandnewcatalysthaswideapplicationprospect.Prominentinrecentyearswereintroducedinthispapertheexperimentandtheorycalculation,theresearchprogressoftransit
4、ionmetalCoclusters,experimentsontheStern-GerlanchdeflectiontechnologyforecastConclustersaveragemagneticspacing,thusfurtherstudyonthemagneticcharacteristicsofclusters,studieshaveshownthatthetemperature,thesizeoftheclusters,andmagneticfieldstrengthofthesefactorstoConmagnetichaveimportantin
5、fluence,Andstudieshaveshownthatclustersofmagneticandtemperature,andpositivelyrelatedtotheintensityofmagneticfield.Andmagneticfirstdecreaseswithincreasethesizeoftheclustersofunchanged,andafterthelaststabletothematerialofmagneticmoment.IntheorytopredictthegroundstateofConstructure,andthend
6、iscussesthemagneticofclusters,studieshaveshownthatthemainfactorsinfluencingthemagneticofConhavesymmetry,theaveragecoordinationnumber,theaveragebondlength.Averagebondlengthandsymmetryandmagneticwerepositivelycorrelated,whilethesizeoftheaveragecoordinationnumberandnegativelycorrelatedwithm
7、agnetic.Experimentsandtheoryprovedthatinacertainnumberofatomicclusterswithinthescopeofmagneticfaroutweighmaterialofmagneticbody,andaftermorethanacertainnumberofatoms,magneticclustersgraduallytothematerialneartheendwiththesamematerialofmagneticbody,thenclustersintomaterial