本文主要研究内容
作者冯中沛(2019)在《基于高通量技术的超导组合薄膜制备及其物性研究》一文中研究指出:以发现Hg金属单质4.2 K的超导电性作为开端,超导领域相关科研探究工作迄今经历了一百多年的发展。它孕育了5次诺贝尔物理学奖,极大推进了关联电子材料、固体物理和相关技术领域的发展与进步,也打开了广阔的应用空间。虽然在传统超导体超导微观机理、高临界温度超导材料探索以及超导材料在能源、医学、信息、交通、国防等方面的应用已取得一系列重大进展,但普适的非常规超导配对机制和常压下的室温超导材料,以及广泛的应用仍是科研工作者们孜孜以求的目标。总之,超导电性作为典型的宏观量子现象,因其所呈现的丰富的物理现象以及奇异的电学、磁学特性,百年来一直是一个具有重要科学意义和重大应用前景的热点研究课题。目前,超导材料研究主要面临着两个重大挑战:1)如果想要实现更高的超导临界转变温度(Critical Temperature,Tc),进入多元化合物领域是不可或缺的途径之一,在数量庞大的多元化合物中排查出具有超导电性的材料是非常艰巨的任务,譬如6种以上元素的随机排列组合,这将会是一个非常惊人的数字;2)对于具有相同元素的化合物,不同的元素配比也会导致样品物性发生明显的改变,这就导致了超导相图具有多样性和复杂性的特征。如果仅仅依靠传统的样品合成方法,不同材料组分一个接一个地合成耗时将会极度漫长!所以超导研究领域面临的关键难题可概括为:多元化合物数据库严重匮乏且相图的多变量特性导致领域内对高温超导的认识仍停留在定性化描述阶段,迫切需要对传统研究模式做出调整。材料基因工程的兴起给关键材料体系的探索和机制认识带来新的机遇,其核心的高通量实验技术能有效加速材料合成与物性表征环节,快速形成材料相图数据库并揭示关键物理规律。材料基因技术与超导领域的交叉将揭开高通量超导研究模式新的篇章。铁基高温超导体和铜氧化合物高温超导体分别保持着常压条件下超导临界温度的次高和最高记录。因此,它们不管是在实际应用还是机理研究方面都有着重要的科研价值。在铁基超导体中,FeSe具有最简单的化学组分和晶体结构,它的二维层状结构是以单一的Fe2Se2超导发生层堆叠而成,但它却呈现出复杂的物理特性,所以一直是铁基超导机理研究的理想载体。FeSe块体的超导转变温度可在小于2 K50 K范围内变化,探究这种变化的内在机制,将为铁基超导机理研究提供重要的参考信息。而高通量超导研究模式又可以为FeSe的物性研究打开新的局面。在铜氧化物高温超导体中,电子型铜氧化高温超导体比空穴型具有更加简洁的相图结构和更低的上临界磁场,是铜基超导机理研究的优良载体。而在电子型铜氧化物超导体中,La2-xCexCuO4±δ是唯一的一个掺杂范围可以覆盖最佳掺杂到极过掺杂Fermi液体区域的体系,所以十分适合组合薄膜研究工作的开展,特别是量子临界现象研究。因此,我们选择FeSe和La2-xCexCuO4±δ作为重点研究对象开展高通量超导研究,预期实现材料库和物性数据库的快速构建,以达到快速形成材料相图数据库并揭示关键物理规律的目的。通过结合脉冲激光沉积(Pulsed Laser Deposition,PLD)、激光分子束外延(Laser Molecular Beam Epitaxy,LMBE)和高通量组合薄膜技术(High-throughput Thin Film Technology),我们大力发展和推广了高通量超导研究模式并分别在铁基超导体FeSe和电子型掺杂的铜氧化物超导体La2-xCexCuO4±δ两个体系上取得了一系列重要的研究进展。1)FeSe薄膜制备均匀FeSe薄膜研制:我们在1500多个样品的沉积制备和表征的经验积累的基础上,成功实现了对薄膜样品质量的精确控制。薄膜样品零电阻转变温度(Zero Resistivity Superconducting Transition Critical Temperature,Tc0)可在小于2 K到14 K连续变化,其中主要的影响因素包括:1)12种不同衬底;2)薄膜的厚度;3)靶材的名义配比;4)激光能量密度;5)激光烧蚀导致靶材表面成分偏析。基于对1500多个薄膜样品数据的系统筛选和统计分析,我们发现薄膜样品Tc与晶格参数c存在一个正相关的依赖关系,而Tc与剩余电阻比(Residual Resistance Ratio,RRR)也呈现正相关的联系,但由于实验背景误差的存在导致数据呈现出较弥散的状态。所以均匀薄膜的实验数据只能给出一个定性的规律。一般情况下人们会认为不同的晶格常数和RRR很可能与不同的Fe、Se比例相关联,所以我们有理由推测微弱的Fe、Se比例变化可能是不同Tc的起因。但由于β-FeSe的超导电性对Fe、Se比例偏析极其敏感,目前常规的化学组分测量手段均不足以满足其测量精度的要求,它们均无法给出直接的化学组分测量结果,也就是说FeSe薄膜的化学计量偏析是在小于1%范围以内的。上述系列高质量FeSe超导薄膜为后续的深入物性研究和应用探索提供重要的样品保障。Tc梯度的FeSe组合薄膜研制:通过开发组合激光制膜技术,我们成功制备出Tc具有连续梯度分布的FeSe组合薄膜样品,也就是成功构建了FeSe薄膜具有Tc梯度的组合材料库。由于不同区域的样品的制备和表征都是在同一个条件和环境下完成的,这不但提高了实验效率,而且还可以极大限度地降低实验背景误差。利用高通量方法得到的组合薄膜数据具有极好的可对比性和准确性,该实验结果快速准确地揭露了FeSe晶格常数c、RRR与Tc准确的正相关依赖关系。以前基于1500多个样品、耗时三年多的工作仍然无法给出精确的实验结果,现在通过高通量组合薄膜技术,只需要一次平行合成和快速连续表征,耗时一周就能完成,而且还能给出更加准确的实验结果。这充分体现了高通量超导研究模式的优越性。沉积温度梯度的FeSe组合薄膜研制:通过在同一块衬底上人为地引入一个温度梯度分布,我们成功制备出具有沉积温度梯度的FeSe组合薄膜样品,也就是成功构建了FeSe薄膜具有沉积温度梯度的组合材料库。与传统的单一沉积温度薄膜不同,沉积温度梯度的FeSe组合薄膜样品可以实现多个沉积温度样品区域的同时平行合成,这不但可以提高实验效率还可以做到更好的单一控制变量,这大幅度地提高实验结果的可对比性和精确度。沉积温度梯度的FeSe组合薄膜实验为后续的新薄膜材料的制备探索提供了新思路。厚度梯度的FeSe组合薄膜研制:利用组合掩模技术,我们成功制备出厚度梯度的FeSe组合薄膜样品,也就是成功构建了FeSe薄膜具有厚度梯度的组合材料库。通过不同厚度FeSe薄膜的同时平行合成,我们实现了薄膜厚度单一变量的严格控制。2)FeSe薄膜物性研究FeSe薄膜常规电阻特性研究:我们对FeSe薄膜进行了一系列精细的温度依赖电阻(Temperature Dependence of Resistance,R-T)测量。在零磁场的R-T输运测量中,我们可以直接获得薄膜样品准确的Tc值和不同温度电阻率数值。再结合R-T数据dR/dT处理结果,我们获得不同Tc薄膜分别在不同温度区域的输运特征。此外,不同磁场下的R-T的拟合结果表明薄膜样品平行ab面和c轴的上临界磁场(Upper Critical Field,Hc2)分别可达66 T和29 T,以及各向异性参数γ=Hc2ab/Hc2c≈2.28,这无疑能为FeSe薄膜的实际应用提供重要的参考。FeSe薄膜磁电阻与霍尔电阻特性:我们对高质量FeSe薄膜样品进行了精细的磁电阻(Magneto Resistance,MR)和霍尔电阻(Hall Resistance,HALL)输运测量,得到了高质量的MR和HALL数据。首先,在整个温度区域FeSe薄膜样品表现出常规金属的磁电阻特性,也就是MR与磁场B成过原点的抛物线关系。其次,在温度恒定的情况下薄膜样品的HALL系数并不会随磁场的增大而发生改变,但HALL系数会随温度降低而发生较大的改变,这表明FeSe薄膜属于多带系统。FeSe薄膜面内磁电阻特性:首先,在正常态的角度依赖的面内磁电阻(In-plane Angular Dependent Magnetoresistivity,AMR,也被称为转角磁电阻)实验中,FeSe薄膜的转角磁电阻在超导态和正常态分别展现出不同的二重旋转对称性演化规律。该二重对称性极可能与向列相有序或结构相变相关,转角磁电阻测量正好能为它们的深入研究提供合适的研究手段。其次,在磁场依赖的面内磁电阻实验中,FeSe薄膜具有与面外的磁电阻不一样的异常行为。FeSe薄膜电子结构、晶格结构与Tc的依赖关系:基于均匀FeSe薄膜实验结果,我们成功获得电子结构随Tc演变的规律。在高温区域,不同Tc的薄膜的HALL系数几乎重合到一起,这表明样品并没有明显的掺杂效果。而且它们只在120 K温度以下开始穿过零点变为正值并开始显示出明显的差异,也就是不同样品具有一致的能带劈裂温度,均为120 K。薄膜解理面的角分辨光电子能谱(Angle Resolved Photoemission Spectroscopy,ARPES)数据给出电子结构演变规律的初步结果,而MR和HALL数据的双载流子Drude-Sommerfeld模型同时拟合结果则进一步成功给出电子和空穴两种载流子浓度在不同温度下的具体数值。随着Tc的增大,低温的空穴载流子浓度没有明显的改变,但电子型载流子浓度则逐渐抬升并超过空穴型载流子,变化可达7倍。这样的电子结构演变规律是简单的费米面填充图像所无法完全解释的,而且不同FeSe薄膜的化学组分差异低于1%,也即是薄膜确实没有明显的掺杂效应。为深入理解上述电子结构演变规律的内在起因,我们把目标转向FeSe薄膜晶格结构的演变规律。均匀FeSe薄膜实验结果只能给出晶格常数a、c和c/a与Tc的定性依赖关系。借助组合薄膜样品数据,我们成功获得FeSe晶格结构常数与Tc0之间更为准确的依赖关系。随着Tc0的增大,面外晶格常数c逐渐增大且变化量为1.1%,而面内晶格常数a则逐渐压缩变化1.3%。利用高通量组合薄膜数据成功获得FeSe晶格结构常数与Tc0之间的准确依赖关系,这是高通量超导研究模式首次在铁基超导研究领域中的应用案例。结合均匀薄膜和高通量组合薄膜的实验结果,我们同时获得了晶格结构、电子结构和Tc三者之间的准确依赖关系。第一性计算实验结果表明晶格结构的变化主要对FeSe薄膜的dxy电子能带结构产生影响。但是dxy轨道只在M点附近穿过费米面,而在Γ点附近它则沉在费米能级以下,所以dxy轨道的变化只会对M点的电子型载流子产生明显的影响,而Γ点附近的空穴型载流子浓度却没有任何改变。上述dxy能带在费米能级处不同的k值响应成功解释了FeSe薄膜电子结构随Tc的演化规律。此外,FeSe薄膜的dxy轨道在费米面的附近的贡献比重逐渐增大而dxz/dyz轨道则逐渐减小,这导致向列相有序被逐步压制,而与向列相有序竞争的超导电性则被逐渐增强。最后,具有原子分辨能力的透射电子显微镜实验数据表明FeSe薄膜的局域晶格畸变是导致宏观晶格结构变化的主要起因。3)La2-xCexCuO4±δ薄膜制备:单一组分的La2-xCexCuO4±δ薄膜研制:我们通过对激光分子束外延过程中不同的工艺参数进行了详尽和精细的探索,实现了La2-xCexCuO4±δ薄膜样品质量的进一步优化。这些高质量薄膜样品的均匀性不管是在空间还是时间上都具有高度的一致性,这为后续的Ce掺杂梯度组合薄膜制备打下了坚实的基础。Ce掺杂梯度La2-xCexCuO4±δ组合薄膜研制:通过严格控制不同组分薄膜均匀性在沉积过程时间和空间上的一致性,并克服长时间的反复退火对La2-xCexCuO4±δ薄膜的不良影响,我们成功制备出不同Ce掺杂分布范围的组合薄膜样品。掺杂分布范围覆盖了最佳掺杂到完全过掺杂整个区域,而且只要探测表征手段具有20μm以下的分辨能力,组合薄膜就可以具有优于0.02%的Ce掺杂组分分辨率。我们成功并快速地构建了La2-xCexCuO4±δ薄膜随Ce掺杂变化的晶格结构数据库和超导电性数据库,而且实验结果表明该系列组合薄膜样品完全能满足量子临界行为研究的要求。以前构建La2-xCexCuO4±δ薄膜Ce掺杂依赖的超导相图,10个不同掺杂的薄膜样品信息需要几百个的薄膜样品沉积合成和表征,耗时需要两年多才能完成。同样的工作,现在通过组合薄膜,只需要少数几次的样品合成和连续表征,耗时只需要两个月就可以完成,大幅度提高实验效率,还可能实现传统研究模式所无法达到的目的,比如对量子临界组分进行无限的逼近并对量子临界现象实施详尽的物性研究。这又一次充分地体现了高通量超导研究模式的强大之处,它的广泛推广定将能够为超导材料研究打开一个全新的局面。
Abstract
yi fa xian Hgjin shu chan zhi 4.2 Kde chao dao dian xing zuo wei kai duan ,chao dao ling yu xiang guan ke yan tan jiu gong zuo qi jin jing li le yi bai duo nian de fa zhan 。ta yun yo le 5ci nuo bei er wu li xue jiang ,ji da tui jin le guan lian dian zi cai liao 、gu ti wu li he xiang guan ji shu ling yu de fa zhan yu jin bu ,ye da kai le an kuo de ying yong kong jian 。sui ran zai chuan tong chao dao ti chao dao wei guan ji li 、gao lin jie wen du chao dao cai liao tan suo yi ji chao dao cai liao zai neng yuan 、yi xue 、xin xi 、jiao tong 、guo fang deng fang mian de ying yong yi qu de yi ji lie chong da jin zhan ,dan pu kuo de fei chang gui chao dao pei dui ji zhi he chang ya xia de shi wen chao dao cai liao ,yi ji an fan de ying yong reng shi ke yan gong zuo zhe men zi zi yi qiu de mu biao 。zong zhi ,chao dao dian xing zuo wei dian xing de hong guan liang zi xian xiang ,yin ji suo cheng xian de feng fu de wu li xian xiang yi ji ji yi de dian xue 、ci xue te xing ,bai nian lai yi zhi shi yi ge ju you chong yao ke xue yi yi he chong da ying yong qian jing de re dian yan jiu ke ti 。mu qian ,chao dao cai liao yan jiu zhu yao mian lin zhao liang ge chong da tiao zhan :1)ru guo xiang yao shi xian geng gao de chao dao lin jie zhuai bian wen du (Critical Temperature,Tc),jin ru duo yuan hua ge wu ling yu shi bu ke huo que de tu jing zhi yi ,zai shu liang pang da de duo yuan hua ge wu zhong pai cha chu ju you chao dao dian xing de cai liao shi fei chang jian ju de ren wu ,pi ru 6chong yi shang yuan su de sui ji pai lie zu ge ,zhe jiang hui shi yi ge fei chang jing ren de shu zi ;2)dui yu ju you xiang tong yuan su de hua ge wu ,bu tong de yuan su pei bi ye hui dao zhi yang pin wu xing fa sheng ming xian de gai bian ,zhe jiu dao zhi le chao dao xiang tu ju you duo yang xing he fu za xing de te zheng 。ru guo jin jin yi kao chuan tong de yang pin ge cheng fang fa ,bu tong cai liao zu fen yi ge jie yi ge de ge cheng hao shi jiang hui ji du man chang !suo yi chao dao yan jiu ling yu mian lin de guan jian nan ti ke gai gua wei :duo yuan hua ge wu shu ju ku yan chong kui fa ju xiang tu de duo bian liang te xing dao zhi ling yu nei dui gao wen chao dao de ren shi reng ting liu zai ding xing hua miao shu jie duan ,pai qie xu yao dui chuan tong yan jiu mo shi zuo chu diao zheng 。cai liao ji yin gong cheng de xing qi gei guan jian cai liao ti ji de tan suo he ji zhi ren shi dai lai xin de ji yu ,ji he xin de gao tong liang shi yan ji shu neng you xiao jia su cai liao ge cheng yu wu xing biao zheng huan jie ,kuai su xing cheng cai liao xiang tu shu ju ku bing jie shi guan jian wu li gui lv 。cai liao ji yin ji shu yu chao dao ling yu de jiao cha jiang jie kai gao tong liang chao dao yan jiu mo shi xin de pian zhang 。tie ji gao wen chao dao ti he tong yang hua ge wu gao wen chao dao ti fen bie bao chi zhao chang ya tiao jian xia chao dao lin jie wen du de ci gao he zui gao ji lu 。yin ci ,ta men bu guan shi zai shi ji ying yong hai shi ji li yan jiu fang mian dou you zhao chong yao de ke yan jia zhi 。zai tie ji chao dao ti zhong ,FeSeju you zui jian chan de hua xue zu fen he jing ti jie gou ,ta de er wei ceng zhuang jie gou shi yi chan yi de Fe2Se2chao dao fa sheng ceng dui die er cheng ,dan ta que cheng xian chu fu za de wu li te xing ,suo yi yi zhi shi tie ji chao dao ji li yan jiu de li xiang zai ti 。FeSekuai ti de chao dao zhuai bian wen du ke zai xiao yu 2 K50 Kfan wei nei bian hua ,tan jiu zhe chong bian hua de nei zai ji zhi ,jiang wei tie ji chao dao ji li yan jiu di gong chong yao de can kao xin xi 。er gao tong liang chao dao yan jiu mo shi you ke yi wei FeSede wu xing yan jiu da kai xin de ju mian 。zai tong yang hua wu gao wen chao dao ti zhong ,dian zi xing tong yang hua gao wen chao dao ti bi kong xue xing ju you geng jia jian jie de xiang tu jie gou he geng di de shang lin jie ci chang ,shi tong ji chao dao ji li yan jiu de you liang zai ti 。er zai dian zi xing tong yang hua wu chao dao ti zhong ,La2-xCexCuO4±δshi wei yi de yi ge can za fan wei ke yi fu gai zui jia can za dao ji guo can za Fermiye ti ou yu de ti ji ,suo yi shi fen kuo ge zu ge bao mo yan jiu gong zuo de kai zhan ,te bie shi liang zi lin jie xian xiang yan jiu 。yin ci ,wo men shua ze FeSehe La2-xCexCuO4±δzuo wei chong dian yan jiu dui xiang kai zhan gao tong liang chao dao yan jiu ,yu ji shi xian cai liao ku he wu xing shu ju ku de kuai su gou jian ,yi da dao kuai su xing cheng cai liao xiang tu shu ju ku bing jie shi guan jian wu li gui lv de mu de 。tong guo jie ge mai chong ji guang chen ji (Pulsed Laser Deposition,PLD)、ji guang fen zi shu wai yan (Laser Molecular Beam Epitaxy,LMBE)he gao tong liang zu ge bao mo ji shu (High-throughput Thin Film Technology),wo men da li fa zhan he tui an le gao tong liang chao dao yan jiu mo shi bing fen bie zai tie ji chao dao ti FeSehe dian zi xing can za de tong yang hua wu chao dao ti La2-xCexCuO4±δliang ge ti ji shang qu de le yi ji lie chong yao de yan jiu jin zhan 。1)FeSebao mo zhi bei jun yun FeSebao mo yan zhi :wo men zai 1500duo ge yang pin de chen ji zhi bei he biao zheng de jing yan ji lei de ji chu shang ,cheng gong shi xian le dui bao mo yang pin zhi liang de jing que kong zhi 。bao mo yang pin ling dian zu zhuai bian wen du (Zero Resistivity Superconducting Transition Critical Temperature,Tc0)ke zai xiao yu 2 Kdao 14 Klian xu bian hua ,ji zhong zhu yao de ying xiang yin su bao gua :1)12chong bu tong chen de ;2)bao mo de hou du ;3)ba cai de ming yi pei bi ;4)ji guang neng liang mi du ;5)ji guang shao shi dao zhi ba cai biao mian cheng fen pian xi 。ji yu dui 1500duo ge bao mo yang pin shu ju de ji tong shai shua he tong ji fen xi ,wo men fa xian bao mo yang pin Tcyu jing ge can shu ccun zai yi ge zheng xiang guan de yi lai guan ji ,er Tcyu sheng yu dian zu bi (Residual Resistance Ratio,RRR)ye cheng xian zheng xiang guan de lian ji ,dan you yu shi yan bei jing wu cha de cun zai dao zhi shu ju cheng xian chu jiao mi san de zhuang tai 。suo yi jun yun bao mo de shi yan shu ju zhi neng gei chu yi ge ding xing de gui lv 。yi ban qing kuang xia ren men hui ren wei bu tong de jing ge chang shu he RRRhen ke neng yu bu tong de Fe、Sebi li xiang guan lian ,suo yi wo men you li you tui ce wei ruo de Fe、Sebi li bian hua ke neng shi bu tong Tcde qi yin 。dan you yu β-FeSede chao dao dian xing dui Fe、Sebi li pian xi ji ji min gan ,mu qian chang gui de hua xue zu fen ce liang shou duan jun bu zu yi man zu ji ce liang jing du de yao qiu ,ta men jun mo fa gei chu zhi jie de hua xue zu fen ce liang jie guo ,ye jiu shi shui FeSebao mo de hua xue ji liang pian xi shi zai xiao yu 1%fan wei yi nei de 。shang shu ji lie gao zhi liang FeSechao dao bao mo wei hou xu de shen ru wu xing yan jiu he ying yong tan suo di gong chong yao de yang pin bao zhang 。Tcti du de FeSezu ge bao mo yan zhi :tong guo kai fa zu ge ji guang zhi mo ji shu ,wo men cheng gong zhi bei chu Tcju you lian xu ti du fen bu de FeSezu ge bao mo yang pin ,ye jiu shi cheng gong gou jian le FeSebao mo ju you Tcti du de zu ge cai liao ku 。you yu bu tong ou yu de yang pin de zhi bei he biao zheng dou shi zai tong yi ge tiao jian he huan jing xia wan cheng de ,zhe bu dan di gao le shi yan xiao lv ,er ju hai ke yi ji da xian du de jiang di shi yan bei jing wu cha 。li yong gao tong liang fang fa de dao de zu ge bao mo shu ju ju you ji hao de ke dui bi xing he zhun que xing ,gai shi yan jie guo kuai su zhun que de jie lou le FeSejing ge chang shu c、RRRyu Tczhun que de zheng xiang guan yi lai guan ji 。yi qian ji yu 1500duo ge yang pin 、hao shi san nian duo de gong zuo reng ran mo fa gei chu jing que de shi yan jie guo ,xian zai tong guo gao tong liang zu ge bao mo ji shu ,zhi xu yao yi ci ping hang ge cheng he kuai su lian xu biao zheng ,hao shi yi zhou jiu neng wan cheng ,er ju hai neng gei chu geng jia zhun que de shi yan jie guo 。zhe chong fen ti xian le gao tong liang chao dao yan jiu mo shi de you yue xing 。chen ji wen du ti du de FeSezu ge bao mo yan zhi :tong guo zai tong yi kuai chen de shang ren wei de yin ru yi ge wen du ti du fen bu ,wo men cheng gong zhi bei chu ju you chen ji wen du ti du de FeSezu ge bao mo yang pin ,ye jiu shi cheng gong gou jian le FeSebao mo ju you chen ji wen du ti du de zu ge cai liao ku 。yu chuan tong de chan yi chen ji wen du bao mo bu tong ,chen ji wen du ti du de FeSezu ge bao mo yang pin ke yi shi xian duo ge chen ji wen du yang pin ou yu de tong shi ping hang ge cheng ,zhe bu dan ke yi di gao shi yan xiao lv hai ke yi zuo dao geng hao de chan yi kong zhi bian liang ,zhe da fu du de di gao shi yan jie guo de ke dui bi xing he jing que du 。chen ji wen du ti du de FeSezu ge bao mo shi yan wei hou xu de xin bao mo cai liao de zhi bei tan suo di gong le xin sai lu 。hou du ti du de FeSezu ge bao mo yan zhi :li yong zu ge yan mo ji shu ,wo men cheng gong zhi bei chu hou du ti du de FeSezu ge bao mo yang pin ,ye jiu shi cheng gong gou jian le FeSebao mo ju you hou du ti du de zu ge cai liao ku 。tong guo bu tong hou du FeSebao mo de tong shi ping hang ge cheng ,wo men shi xian le bao mo hou du chan yi bian liang de yan ge kong zhi 。2)FeSebao mo wu xing yan jiu FeSebao mo chang gui dian zu te xing yan jiu :wo men dui FeSebao mo jin hang le yi ji lie jing xi de wen du yi lai dian zu (Temperature Dependence of Resistance,R-T)ce liang 。zai ling ci chang de R-Tshu yun ce liang zhong ,wo men ke yi zhi jie huo de bao mo yang pin zhun que de Tczhi he bu tong wen du dian zu lv shu zhi 。zai jie ge R-Tshu ju dR/dTchu li jie guo ,wo men huo de bu tong Tcbao mo fen bie zai bu tong wen du ou yu de shu yun te zheng 。ci wai ,bu tong ci chang xia de R-Tde ni ge jie guo biao ming bao mo yang pin ping hang abmian he czhou de shang lin jie ci chang (Upper Critical Field,Hc2)fen bie ke da 66 The 29 T,yi ji ge xiang yi xing can shu γ=Hc2ab/Hc2c≈2.28,zhe mo yi neng wei FeSebao mo de shi ji ying yong di gong chong yao de can kao 。FeSebao mo ci dian zu yu huo er dian zu te xing :wo men dui gao zhi liang FeSebao mo yang pin jin hang le jing xi de ci dian zu (Magneto Resistance,MR)he huo er dian zu (Hall Resistance,HALL)shu yun ce liang ,de dao le gao zhi liang de MRhe HALLshu ju 。shou xian ,zai zheng ge wen du ou yu FeSebao mo yang pin biao xian chu chang gui jin shu de ci dian zu te xing ,ye jiu shi MRyu ci chang Bcheng guo yuan dian de pao wu xian guan ji 。ji ci ,zai wen du heng ding de qing kuang xia bao mo yang pin de HALLji shu bing bu hui sui ci chang de zeng da er fa sheng gai bian ,dan HALLji shu hui sui wen du jiang di er fa sheng jiao da de gai bian ,zhe biao ming FeSebao mo shu yu duo dai ji tong 。FeSebao mo mian nei ci dian zu te xing :shou xian ,zai zheng chang tai de jiao du yi lai de mian nei ci dian zu (In-plane Angular Dependent Magnetoresistivity,AMR,ye bei chen wei zhuai jiao ci dian zu )shi yan zhong ,FeSebao mo de zhuai jiao ci dian zu zai chao dao tai he zheng chang tai fen bie zhan xian chu bu tong de er chong xuan zhuai dui chen xing yan hua gui lv 。gai er chong dui chen xing ji ke neng yu xiang lie xiang you xu huo jie gou xiang bian xiang guan ,zhuai jiao ci dian zu ce liang zheng hao neng wei ta men de shen ru yan jiu di gong ge kuo de yan jiu shou duan 。ji ci ,zai ci chang yi lai de mian nei ci dian zu shi yan zhong ,FeSebao mo ju you yu mian wai de ci dian zu bu yi yang de yi chang hang wei 。FeSebao mo dian zi jie gou 、jing ge jie gou yu Tcde yi lai guan ji :ji yu jun yun FeSebao mo shi yan jie guo ,wo men cheng gong huo de dian zi jie gou sui Tcyan bian de gui lv 。zai gao wen ou yu ,bu tong Tcde bao mo de HALLji shu ji hu chong ge dao yi qi ,zhe biao ming yang pin bing mei you ming xian de can za xiao guo 。er ju ta men zhi zai 120 Kwen du yi xia kai shi chuan guo ling dian bian wei zheng zhi bing kai shi xian shi chu ming xian de cha yi ,ye jiu shi bu tong yang pin ju you yi zhi de neng dai pi lie wen du ,jun wei 120 K。bao mo jie li mian de jiao fen bian guang dian zi neng pu (Angle Resolved Photoemission Spectroscopy,ARPES)shu ju gei chu dian zi jie gou yan bian gui lv de chu bu jie guo ,er MRhe HALLshu ju de shuang zai liu zi Drude-Sommerfeldmo xing tong shi ni ge jie guo ze jin yi bu cheng gong gei chu dian zi he kong xue liang chong zai liu zi nong du zai bu tong wen du xia de ju ti shu zhi 。sui zhao Tcde zeng da ,di wen de kong xue zai liu zi nong du mei you ming xian de gai bian ,dan dian zi xing zai liu zi nong du ze zhu jian tai sheng bing chao guo kong xue xing zai liu zi ,bian hua ke da 7bei 。zhe yang de dian zi jie gou yan bian gui lv shi jian chan de fei mi mian tian chong tu xiang suo mo fa wan quan jie shi de ,er ju bu tong FeSebao mo de hua xue zu fen cha yi di yu 1%,ye ji shi bao mo que shi mei you ming xian de can za xiao ying 。wei shen ru li jie shang shu dian zi jie gou yan bian gui lv de nei zai qi yin ,wo men ba mu biao zhuai xiang FeSebao mo jing ge jie gou de yan bian gui lv 。jun yun FeSebao mo shi yan jie guo zhi neng gei chu jing ge chang shu a、che c/ayu Tcde ding xing yi lai guan ji 。jie zhu zu ge bao mo yang pin shu ju ,wo men cheng gong huo de FeSejing ge jie gou chang shu yu Tc0zhi jian geng wei zhun que de yi lai guan ji 。sui zhao Tc0de zeng da ,mian wai jing ge chang shu czhu jian zeng da ju bian hua liang wei 1.1%,er mian nei jing ge chang shu aze zhu jian ya su bian hua 1.3%。li yong gao tong liang zu ge bao mo shu ju cheng gong huo de FeSejing ge jie gou chang shu yu Tc0zhi jian de zhun que yi lai guan ji ,zhe shi gao tong liang chao dao yan jiu mo shi shou ci zai tie ji chao dao yan jiu ling yu zhong de ying yong an li 。jie ge jun yun bao mo he gao tong liang zu ge bao mo de shi yan jie guo ,wo men tong shi huo de le jing ge jie gou 、dian zi jie gou he Tcsan zhe zhi jian de zhun que yi lai guan ji 。di yi xing ji suan shi yan jie guo biao ming jing ge jie gou de bian hua zhu yao dui FeSebao mo de dxydian zi neng dai jie gou chan sheng ying xiang 。dan shi dxygui dao zhi zai Mdian fu jin chuan guo fei mi mian ,er zai Γdian fu jin ta ze chen zai fei mi neng ji yi xia ,suo yi dxygui dao de bian hua zhi hui dui Mdian de dian zi xing zai liu zi chan sheng ming xian de ying xiang ,er Γdian fu jin de kong xue xing zai liu zi nong du que mei you ren he gai bian 。shang shu dxyneng dai zai fei mi neng ji chu bu tong de kzhi xiang ying cheng gong jie shi le FeSebao mo dian zi jie gou sui Tcde yan hua gui lv 。ci wai ,FeSebao mo de dxygui dao zai fei mi mian de fu jin de gong suo bi chong zhu jian zeng da er dxz/dyzgui dao ze zhu jian jian xiao ,zhe dao zhi xiang lie xiang you xu bei zhu bu ya zhi ,er yu xiang lie xiang you xu jing zheng de chao dao dian xing ze bei zhu jian zeng jiang 。zui hou ,ju you yuan zi fen bian neng li de tou she dian zi xian wei jing shi yan shu ju biao ming FeSebao mo de ju yu jing ge ji bian shi dao zhi hong guan jing ge jie gou bian hua de zhu yao qi yin 。3)La2-xCexCuO4±δbao mo zhi bei :chan yi zu fen de La2-xCexCuO4±δbao mo yan zhi :wo men tong guo dui ji guang fen zi shu wai yan guo cheng zhong bu tong de gong yi can shu jin hang le xiang jin he jing xi de tan suo ,shi xian le La2-xCexCuO4±δbao mo yang pin zhi liang de jin yi bu you hua 。zhe xie gao zhi liang bao mo yang pin de jun yun xing bu guan shi zai kong jian hai shi shi jian shang dou ju you gao du de yi zhi xing ,zhe wei hou xu de Cecan za ti du zu ge bao mo zhi bei da xia le jian shi de ji chu 。Cecan za ti du La2-xCexCuO4±δzu ge bao mo yan zhi :tong guo yan ge kong zhi bu tong zu fen bao mo jun yun xing zai chen ji guo cheng shi jian he kong jian shang de yi zhi xing ,bing ke fu chang shi jian de fan fu tui huo dui La2-xCexCuO4±δbao mo de bu liang ying xiang ,wo men cheng gong zhi bei chu bu tong Cecan za fen bu fan wei de zu ge bao mo yang pin 。can za fen bu fan wei fu gai le zui jia can za dao wan quan guo can za zheng ge ou yu ,er ju zhi yao tan ce biao zheng shou duan ju you 20μmyi xia de fen bian neng li ,zu ge bao mo jiu ke yi ju you you yu 0.02%de Cecan za zu fen fen bian lv 。wo men cheng gong bing kuai su de gou jian le La2-xCexCuO4±δbao mo sui Cecan za bian hua de jing ge jie gou shu ju ku he chao dao dian xing shu ju ku ,er ju shi yan jie guo biao ming gai ji lie zu ge bao mo yang pin wan quan neng man zu liang zi lin jie hang wei yan jiu de yao qiu 。yi qian gou jian La2-xCexCuO4±δbao mo Cecan za yi lai de chao dao xiang tu ,10ge bu tong can za de bao mo yang pin xin xi xu yao ji bai ge de bao mo yang pin chen ji ge cheng he biao zheng ,hao shi xu yao liang nian duo cai neng wan cheng 。tong yang de gong zuo ,xian zai tong guo zu ge bao mo ,zhi xu yao shao shu ji ci de yang pin ge cheng he lian xu biao zheng ,hao shi zhi xu yao liang ge yue jiu ke yi wan cheng ,da fu du di gao shi yan xiao lv ,hai ke neng shi xian chuan tong yan jiu mo shi suo mo fa da dao de mu de ,bi ru dui liang zi lin jie zu fen jin hang mo xian de bi jin bing dui liang zi lin jie xian xiang shi shi xiang jin de wu xing yan jiu 。zhe you yi ci chong fen de ti xian le gao tong liang chao dao yan jiu mo shi de jiang da zhi chu ,ta de an fan tui an ding jiang neng gou wei chao dao cai liao yan jiu da kai yi ge quan xin de ju mian 。
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论文作者分别是来自中国科学院大学(中国科学院物理研究所)的冯中沛,发表于刊物中国科学院大学(中国科学院物理研究所)2019-07-19论文,是一篇关于材料基因工程论文,高通量组合薄膜论文,脉冲激光沉积论文,激光分子束外延论文,铁基高温超导体论文,铜氧化物高温超导体论文,中国科学院大学(中国科学院物理研究所)2019-07-19论文的文章。本文可供学术参考使用,各位学者可以免费参考阅读下载,文章观点不代表本站观点,资料来自中国科学院大学(中国科学院物理研究所)2019-07-19论文网站,若本站收录的文献无意侵犯了您的著作版权,请联系我们删除。
标签:材料基因工程论文; 高通量组合薄膜论文; 脉冲激光沉积论文; 激光分子束外延论文; 铁基高温超导体论文; 铜氧化物高温超导体论文; 中国科学院大学(中国科学院物理研究所)2019-07-19论文;