原子吸收限附近Bragg情况的衍射波和透射波的观测

在Ｇａ的Ｋ吸收限附近的强反常散射条件下，测定了ＧａＡｓ（６００）对称Ｂｒａｇｇ情况的衍射波和透射波的摇摆曲线，并将其和Ｘ射线衍射动力学理论的相应计算结果作了比较，指出了原子吸收限附近Ｂｒａｇｇ情况的透射波在研究反常散射中的应用价值 关键词：     

GaAs半导体材料中双光子吸收光限幅与偏振方向的关系

理论分析了线偏振光波的偏振方向对ＧａＡｓ半导体双光子吸收的影响，实现了ＧａＡｓ半导体材料中不同偏振方向的双光子吸收限幅，提高了双光子吸收光限幅的性能。     

垂直电子耦合InGaAs量子吉的光学特性

报导了ＩｎＧａＡｓ／ＧａＡｓ和ＩｎＧａＡｓ／ＡｌＧａＡｓ垂直耦合量子结在注入式激光器的制备工艺及其光致荧光谱，量热吸收谱和电致荧光谱的特性，该激光器的连续波波发光功率在室温下可达１Ｗ。     

高功率808nm InGaAsP—GaAs分别限制结构的半导体激光器

介绍了研究分别限制结构ＩｎＧａＡｓＰ－ＧａＡｓ半导体激光器所得到的最新成果。利用引进的俄国技术，基于量子阱结构的ＩｎＧａＡｓＰ－ＧａＡｓ激光器，可用短时间液相外延技术制造。在ＧａＡｓ衬底上制成的ＩｎＧａＡｓＰ－ＧａＡｓ分别限制结构的激光器，主要参数如下：发射波入λ＝８０８ｎｍ，阈值电流密度Ｊ＝３００Ａ／ｃｍ＾２，对于条宽ω＝１００μｍ的激光器，连续功率为１－２Ｗ。     

三种固态六氟化镓离子化合物的远红外光谱研究

用傅里叶变换红外光谱法研究了Ｒｂ３ＧａＦ６，室温相αＣｓ３ＧａＦ６和高温相Ｃｓ３ＧａＦ６冰晶石类氟化物的远红外光谱，地它们的光谱带进行了指认，并进行了Ｘ射线衍射分析，结果表明，Ｒｂ３ＧａＦ６与高温相Ｃｓ３ＧａＦ６同属四方晶系，晶胞参数分别为ａ＝６．３２，ｃ－８．８６Ａ和ａ＝６．８７，ｃ＝９．８７Ａ，α－Ｃｓ３ＧａＦ６属正交晶系，ａ＝１０．６２，ｂ＝９．９６，ｃ＝５．６１Ａ。     

GaAs衬底上生长的GaInP_2外延单晶薄膜的杂质污染研究

各种外延技术已被用来在ＧａＡｓ衬底上生长ＧａｘＩｎ１－ｘＰ外延单晶薄膜（ＧａＩｎＰ２／ＧａＡｓ）．很多文献认为,在ＧａＩｎＰ２／ＧａＡｓ生长过程中会被Ｃ杂质污染．我们用高灵敏的ＣＡＭＥＣＡＩＭＳ４Ｆ型二次离子质谱仪直接测量的结果表明,污染ＧａＩｎＰ２／ＧａＡｓ的微量杂质是Ｓｉ,而不是Ｃ．由ＧａＩｎＰ２／ＧａＡｓ在１．１７ｅＶ附近的光致发光峰的峰值随激发强度的变化形状表明了它应属于施主－受主对复合发光．进一步分析表明,施主为处在Ｇａ格位上的Ｓｉ杂质（ＳｉＧａ）,受主为Ｇａ空位（ＶＧａ）．     

磁场下对近藤绝缘体CeNiSn的研究

测量了ＣｅＮｉＳｎ的一系列磁物性，发现在４．５Ｋ下，ＣｅＮｉＳｎ的磁化曲线在３Ｔｅｓｌａ处有拐点，并且发现４Ｔｅｓｌａ磁场可以压抑４００Ｇａｓｓ磁场下测量的磁化率随温度变化曲线在１０Ｋ附近的峰，但磁阻测量表明４Ｔｅｓｌａ磁场并没有改变ＣｅＮｉＳｎ的近藤绝缘体性质．说明磁化率曲线在１０Ｋ附近的峰的形成与近藤绝缘体的形成无本质联系，磁场对能隙的影响中，Ｚｅ－ｍａｎ劈裂的作用并不强，而主要是通过破坏形成准粒子的局域ｆ电子与ｃ电子相互作用而达到压抑能隙的．     

用透射电子显微镜观察GF－AAS中作为基体改进剂的锡或铟与钯的金属间化合物的汽体

用透射电子显微镜观察ＧＦ－ＡＡＳ中作为基体改进剂的锡或铟与钯的金属间化合物的汽体ＹＡＳＶＤＡＫａｚｕｏ１，ＨＩＲＡＮＯＹｏｓｈｉｈｉｒｔｏ１ａｎｄＨＩＲＯＫＡＷＡＫｉｃｈｉｎｏｓｕｋｅ２日本日立有限公司测试设备部，３１２．茨城县日本日本东北大学材料研...     

1MeVSi~＋衬底加温注入Al＿（0．3）Ga＿（0．7）As／GaAs超晶格和GaAs的晶格损伤研究

用卢瑟福背散射／沟道技术研究了１ＭｅＶＳｉ￣＋在衬底加温和室温下以不同剂量注入Ａｌ＿（０．３）Ｇ＿（０．７）Ａｓ／ＧａＡｓ超晶格和ＧａＡｓ后的晶格损伤。在衬底加温下，观察到Ａｌ＿（０．３）Ｇａ＿（０．７）Ａｓ／ＧａＡｓ超晶格和ＧａＡｓ都存在一个动态退火速率与缺陷产生速率相平衡的剂量范围，以及两种速率失去平衡的临界剂量。超晶格比ＧａＡｓ更难以损伤，并且它的两种速率失去平衡的临界剂量也大于ＧａＡｓ中的相应临界剂量，用热尖峰与碰撞模型解释了晶格损伤积累与注入剂量和衬底温度的关系。用ＣＮＤＯ／２量子化学方法计算了ＧａＡｓ和Ａｌ＿ｘＧａ＿（１－ｘ）Ａｓ中化学键的相对强度，并根据计算结果解释了注入过程中Ａｌ＿（０．３）Ｇａ＿（０．７）Ａｓ／ＧａＡｓ超晶格和ＧａＡｓ中晶格损伤程度的差别。     

GaAlAs／GaAs量子阱结构的实验研究

利用分子束外延生长法生长出了ＧａＡｌＡｓ／ＧａＡｓ梯度折射率分别限制单量子阱结构材料，对样品进行了光荧光谱、双晶Ｘ射线衍射和电化学电容－电压分布测量。实验结果表明，样品质量达到了设计要求，利用该材料制作的激光二极管获得了初步结果。     

GaAs/Ge的MOCVD生长研究

用常压MOCVD在Ge衬底上外延生长了GaAs单晶层,研究了GaAs和6e的极性与非极性材料异质外延生长,获得了质量优良的GaAs/Ge外延片,GaAs外延层X射线双晶衍射回摆曲线半高宽达16弧秒.10K下PL谱半峰宽为7meV.讨论了极性与非极性外延的界面反相畴问题和GaAs-Ge界面的Ga、Ge原子互扩散问题.     

Assessment of mismatched epitaxial layers by X-ray rocking curve measurements and simulations

In the design of heteroepitaxial systems the knowledge of composition, strain and thickness of the various layers involved is of great importance. The determination of these structural parameters is among the applications most common in high-resolution X-ray diffraction. Numerical simulation of rocking curves has emerged as an important aid in the determination of the relevant structural parameters. Based upon the dynamical theory of X-ray diffraction a FORTRAN program has been written to simulate and refine structural parameters from rocking curve data. X-ray rocking curve analysis has been used to develop and optimize MOCVD-growth of Ga_xIn_1-xP/GaAs heteroepitaxial systems. We observed superlattice peaks in samples of low misfit. With the aid of computer simulations we attribute these to unintentional periodic compositional fluctuations (Ga/In) of the order of 1%.     

Characterization of (In,Ga)As/GaAs strained-layer multiple quantum wells with high-resolution X-ray diffraction and computer simulations

Pseudomorphic, highly strained (In,Ga)As/GaAs multiple quantum well structures were grown by molecular beam epitaxy and characterized by high-resolution X-ray diffraction. Thickness, lattice mismatch and chemical composition of the quantum wells were determined from measurements of satellite Bragg reflections and comparison with calculated rocking curves. In periodic structures, quantum wells with a width of less than 10 nm can be characterized by this technique. The results are compared with transmission electron microscopy, optical absorption and optical emission spectroscopy.     

Be掺杂对InGaAsN/GaAs量子阱性能的提高

InGaAsN/GaAs量子阱中进行铍(Be)元素重掺杂能显著提高其光学性质,并且发光波长发生了红移.X射线衍射摇摆曲线清楚地证实了铍掺杂抑制了InGaAsN(Be)/GaAs量子阱在退火过程中的应力释放.对比退火前,退火后的没有进行铍掺杂的量子阱样品的量子阱的X射线摇摆曲线衍射峰明显向GaAs衬底峰偏移;而对于掺铍的量子阱样品而言,这样的偏移要小很多.     

X-ray double-crystal rocking curves in GaAlAs/GaAs heterostructures

Summary X-ray double-crystal rocking curves of Ga_1−x Al _x As/GaAs heterostructures have been calculated using a dynamical diffraction model for the general case of Bragg reflection geometry. Different experimental configurations have been considered and the possibility of studying both slightly mismatched and relatively thin layers has been investigated. Experimental rocking curves have been measured using the CuKα ₁ radiation, the 004 symmetric reflection and a perfect crystal as the monochromator. An excellent agreement between calculated and experimental rocking curves has been found and this demonstrates the reliability of both the experimental procedure and the theoretical approach.     

X-Ray double crystal rocking curves of Ga1−x Al x As/GaAs laser structures

Summary The double crystal X-ray rocking curves of Ga_1−x Al _x As/GaAs laser structures, with both a single and double confinement, have been calculated on the basis of the Takagi-Taupin dynamica theory. It has been demonstrated that very small changes in the thickness and composition of the active and the internal confining layers give rise to dramatic modifications of the rocking curves; this offers in principle a very powerful tool for measuring very precisely thickness and composition of these layers. However, the shape of the Bragg peak of the external confining layers exhibits a nearly period behaviour as a function of the thickness of the active or the internal confining layer; a simple relation between the thickness period and the composition difference of the considered layers has been obtained for the first time. Finally, the effect of the interchange of the confining layers on the rocking curves has been discussed.     

应变弛豫InGaAs/GaAs超晶格的X射线双晶衍射及形貌研究

应用X射线双晶衍射及双晶形貌术,对应变弛豫的InGaAs/GaAs超晶格作了研究,通过对双晶衍射摇摆曲线的计算机模拟,得到了超晶格的结构,应变弛豫机制,弛豫比,超晶格层与衬底的取向差等重要参数。从双晶形貌,得到了超晶格与衬底界面处和超晶格中的位错分布。 关键词：     

透射式GaAs光电阴极AlGaAs/GaAs外延层X射线衍射摇摆曲线研究

利用透射式GaAs光电阴极AlGaAs/GaAs外延层的结构特点及其X射线衍射摇摆曲线分析方法,解释了AlGaAs/GaAs外延层摇摆曲线半峰宽和其衍射角角位移随外延层生长温度升高而增大的现象.     

Phase relations in analysis of glancing incidence X-ray rocking curves from superlattices

Nontrivial features of the formation of glancing incidence x-ray rocking curves from superlattices are revealed and analyzed for the magnetic digital alloy GaSb/15(Mn/GaSb)/GaAs. The qualitative analysis of the shape of the experimental curve in the framework of specific phase relations in the reflection amplitude makes it possible not only to describe these features, in particular, the two-humped profile of the first Bragg peak and to reconstruct the real structure of the alloys under investigation, but also to develop the general scheme for analyzing x-ray rocking curves from imperfect superlattices.