HDDR过程中三元和多元Nd-Fe-B合金磁畴结构的MFM研究

用磁力显微镜研究了三元Nd-Fe-B合金在HDDR过程的不同阶段(铸态、不充分吸氢歧化、充分吸氢歧化和脱氢再复合)的破畴结构。在铸态样品表面清楚地观察到了易磁化轴互相垂直的柱状晶表面的两类磁畴图型。当样品不充分吸氢歧化和充分吸氢歧化时，破畴结构明显发生变化，反映了Nd-Fe-B的分解产物NdH2，α-Fe和Fe2B及其微晶结构的变化。脱氢再复合后形成的微晶的磁畴结构则表明样品保留了铸态样品柱状晶的构型。此外，还对比研究了多元Nd-Fe-B合金在HDDR过程中的磁畴结构，并根据微磁结构分析，指出过量的Ga元素添加可抑制Nd2(Fe，M)14B相的吸氢歧化，从而导致相应HDDR粘结磁体性能降低。     

Organic quantum well and superlattice characteristics in quasi-one-dimensional multiblock copolymers

A tight-binding calculation was presented to describe multiblock copolymers, such as [...-(PA)x-(PPP)y-...] composed of PA (polyacetylene) and PPP (poly(p-phenylene). It is found that a copolymer has a quantum well and superlattice characteristics, and evident is the effect of the composite lengths, the interfacial couplings and the electron-phonon interactions on the electronic properties of a copolymer. The quantum tunneling, the Franz-Keldysh effect and the quantum confinement can be generated under an applied electric field. These results were compared to those of traditional inorganic quantum well and superlattice systems.     

聚合物基片对柔性有机发光器件性能的影响

以聚合物基片柔性ITO膜为透明电极，制备了ITO／TPD／Alq3／Al结构柔性有机发光器件，并与在相同条件下制备的玻璃基片相同结构器件作了比较。研究了不同基片对有机材料及器件性能的影响，指出选择不易吸湿、耐温高、热胀系数小的聚合物材料，提高柔性ITO膜的附着力和导电性，结合柔性ITO膜的具体特性。优化有机层的蒸镀条件，是提高柔性有机发光器件发光亮度和稳定性的重要途径。     

一种硅原子簇边界处理方法

近年来,用量子化学—原子簇方法研究固体的电子性质,例对固体表面、体内杂质和缺陷、无序体系的电子结构等的研究越来越引起人们的重视。原子簇模型的基本思想是以有限大的原子团模拟无限大的体系。共价固体硅原子簇边界悬挂键的处理,对计算结果影响很大。边界饱和原子的选取,是原子簇方法中一个十分重要的问题。Tong曾用氢原子饱和边界,发现所计算的电子态密度结果中禁带较宽;张开     

Magnetic Microstructures of PryFe90－yB10 （y = 8－11.76） Nanocrystalline Ribbons Using Magnetic Force Microscopy ＊

Magnetic microstructure of melt-spun PryFe90-yB10 (y = 8, 8.5, 9, 9.5, 10 and 11.76) nanocrystalline ribbons in an as-grown state has been studied using a magnetic force microscope. The magnetic domains are characterized by dark areas adjacent to bright areas in a sub-micron scale and in random distribution. By comparing with the size of the micro-crystals measured from the TEM image, the exchange coupling effect was confirmed to exist inall the ribbons. Using the roughness analysis, the variation of the root mean-square values of the phase shifts obtained from the magnetic force images versus the content y of Pr were measured, which is very consistent with the curve of the residual induction Bγ versus the content y.     

Alq3有机发光器件的研制及寿命研究

以铟锡氧化物 (ITO)为透明电极 ,8 羟基喹啉铝 (Alq3)为发光层 ,研制成ITO/Alq3/Al结构有机电致发光器件 (OLED) .测量表明其载流子的注入满足隧穿理论 ,发光阈值电压～ 1 2V ,所发绿光在正常室内环境下清晰可见 .通过电流随时间的变化测量了器件的工作寿命 ,并对影响器件寿命的原因作了分析 .     

准一维多嵌段共聚物有机量子阱和超晶格特征

在紧束缚模型的基础上, 研究了由聚乙炔(PA)和聚对苯撑(PPP)组成的准一维多嵌段共聚物系列材料的电子特性, 发现它们具有量子阱或超晶格特征. 各单体的尺度、单体间界面耦合以及电子-声子相互作用的强弱对共聚物的电子性质都有显著的影响, 与传统半导体量子阱和超晶格相似, 沿链方向外加电场的作用, 可导致量子隧穿的发生以及Franz-Keldysh效应和量子约束效应的出现.     

Organic quantum-well characteristics of quasi-one-dimensional copolymers

Copolymers which are synthesized by oligomers or homopolymers have quasi-one-dimensional structures. A tight-binding model was suggested to study the organic quantum-well properties of triblock copolymers xPA/nPPP/yPA and xPPP/nPA/yPPP consisting of polyacetylene (PA) and poly( p-phenylene) (PPP). It was found that the electronic density in the lowest conductive state (LUMO) could be tuned by the ratios of homopolymers and interfacial coupling. The spontaneous quantum tunneling effects will occur in triblock copolymer xPA/nPPP/yPA with the increasing interfacial coupling.