背散射技术用于表面微分析

引 言 用离子加速器的离子束进行物质分析是近十年发展起来的有效的实验方法.它包括背散射、质子荧光分析和核反应三种方法.这些方法各有特点,互相补充[1],背散射用来分析样品表面下组成的变化或着杂质的深度分布特别合适.其主要优点是简便、直观、定量、可靠,对样品无损伤.与其它方法相比,既不需要对样品进行麻烦的剥层处理(例如离子溅射、化学腐蚀或研磨等),也不需霎依赖“标样”.使用l-2兆电子伏的4He离子束分析样品深度可达几千埃(采用质子束可增加分析深度达几个微米),通常深度分辨率可达200埃左右(采用掠角散射,深度分辨率可达20—30…     

用主量化学组成研究汝官瓷和钧官瓷的原料来源

将84个清凉寺窑汝官瓷和钧台窑钧官瓷样品进行质子激发X射线荧光分析,得到每个样品胎和釉的7种主量化学组分。将所有样品的7种主量化学组成数据进行散布分析,以确定汝官瓷和钧官瓷原料来源是否相同。从散布分析图可以看出,汝官瓷釉和 钧官瓷釉样品的原料产地和配方明显不同,汝官瓷胎和钧官瓷胎样品的原料产地和成分接近,但有所不同。The seven main chemical components of the body and glaze samples of 84 RuGuan porcelains from Qingliangsi kiln and JunGuan porcelains from Juntai kiln are determined by the proton induced X-ray emission （ PIXE）. Then these data are analyzed by scatter analysis to confirm whether the sources of the raw materials of Ru-Guan porcelain from Qingliangsi kiln and JunGuan porcelain from Juntai kiln are the same or not. The figure of the scatter diagram shows that the sourcing area of the raw material and batch formula of RuGuan porcelain and Jun-Guan porcelain glaze are obviously different and the sources of the raw materials and components of their body samples are close but a bit different.     

Nondestructive identification of ancient Chinese glasses by Raman and proton-induced X-ray emission spectroscopy

Nondestructive Raman spectroscopy and external-beam proton-induced X-ray emission (PIXE) technique to analyze eight ancient glasses unearthed from the provinces of Henan,Hubei,and Jiangsu,which allowes for a good characterization of the glass matrix and chemical compositions,is carried out.The results indicate that all the eight glass samples could be typically divided into three systems: faience (sample No.SZWG-4),PbO-BaO-SiO 2 (sample Nos.NYWKI-5-1,HNWKII-88,and HNWKII-84),and Na 2 OCaO-SiO 2 (sample Nos.HBWKI-16,HBWKI-17,HBWKI-18,and SZWG-1).Additional relationships between the Raman spectra and parameters,such as residues of raw materials and opacifying agent,are also discussed by respectively comparing them with similar glass samples excavated from other historical sites.     

RADIATION-INDUCED DAMAGE IN GaP BY MeV HELIUM IONS

The creation of defects in GaP bombarded with MeV ⁴He ions has been studied under ultra-high-vacuum condition by Rutherford backscattering/channeling (RBS/C) method, and the absolute damage cross section σ_d for GaP has been determined under bombardment of 1.0 MeV ⁴He ions, with the measured value 8.0xl0^-18 cm². Our experimental results suggest that the defect generation rate is strongly related to the surface condition. When the GaP covered with a thin amorphous layer, a significant ion beam annealing effect will be observed. The present results show that for GaP the damage is produced mainly by nuclear collision.     

氧化铝与Al(100)基体间界面原子结构研究

本文介绍了用MeV离子散射和沟道效应研究单晶铝表面无定型氧化层与基体之间界面原子结构的方法。报道了Al₂O₃/Al(100)界面原子结构的实验结果。实验表明,在纯氧气氛围中400℃下生成的氧化铝膜,铝和氧原子浓度比例严格为2与3之比;Al₂O₃膜和Al(100)基体之间的界面极其陡峭,氧化铝膜下Al(100)基体表面的再构层不大于一个原子层。由实验测量与用Monte Carlo方法计算结果比较,得到再构层原子离开原来晶 关键词：     

氧化铝与Al(100)基体间界面原子结构研究

本文介绍了用MeV离子散射和沟道效应研究单晶铝表面无定型氧化层与基体之间界面原子结构的方法。报道了Al_2O_3/Al(100)界面原子结构的实验结果。实验表明,在纯氧气氛围中400℃下生成的氧化铝膜,铝和氧原子浓度比例严格为2与3之比;Al_2O_3膜和Al(100)基体之间的界面极其陡峭,氧化铝膜下Al(100)基体表面的再构层不大于一个原子层。由实验测量与用Monte Carlo方法计算结果比较,得到再构层原子离开原来晶格位置距离为0.18埃。室温下,Al(100)氧吸附层的元素成份在氧原子覆盖度较低时主要为AlO。     

碳对α的非卢瑟福背散射截面研究

报道了散射角为１７０°±１．５°，α粒子能量在５－９．０ＭｅＶ之间，ｃ的背散射截面的实验测量值；用Ｒ矩阵理论，通过与实验数据拟合，分析、给出了一套能级参数，并计算了能量范围在２－９．０ＭｅＶ，ｃ的背散射截面；讨论了对背散射分析感兴趣的窄而孤立的强共振峰４２５０±１０ＫｅＶ随靶厚、角度的变化关系以及截面变化缓慢的平坦区３．６－４．２０ＭｅＶ，６．４２５－６．７００ＭｅＶ能区的截面值与背散射角度的关系。 关键词：     

109Cd源激发的X射线荧光法无创伤测定人体骨铅含量

建立了用以体内测定骨铅含量的109Cd源作为激发源的X射线荧光测量系统. 该系统采用高纯锗探测器(10 mm×7 mm), 检测人体胫骨中铅被109Cd的88.0 keV的γ射线激发后产生的特征K层X射线. 采用铅的K层X射线对相干散射归一化的方法, 根据铅的K层X射线强度与相干散射强度的比值对胫骨模型铅含量之间的校正曲线, 便可得到人体骨铅的含量. 这种归一化的方法, 使测量结果的精确度不受骨外组织层厚度、骨的形状、大小、密度以及被测者位移的影响. 用含铅石膏制作的一组胫骨模型得到的校正曲线呈现良好的线性关系. 对急性铅中毒工人的试验性测量结果表明, 他们的骨铅含量明显高于对照组.     

低能沟道效应及其应用

带电粒子在晶体中的运动会受到沟道效应和阻塞效应的强烈影响。本文评述了能量为Mev的质子和氦离子在晶体中的沟道效应及其在固体物理、半导体物理、表面物理和原子物理中的应用,同时也叙述了我们实验室在近几年来得到的各种实验结果。