Ion beam methods

1 The interaction of energetic ions with matter - introducing the 

In secondary ion mass spectrometry (SIMS) ions with energies in the kilo-electron-volt range consitute the probe. The penetrating power of these ions is rather small and the majority of the ion-matter interaction takes place in the 

In a quadrupole SIMS instrument one can typically detect ions up to 1000 in relative molecular mass. The detailed mechanisms that underly sputtering are 

As mentioned above, the determining factor that allows one to obtain 

Dynamic SIMS is an extremely well-established and widely used depthprofiling technique for the study of inorganic materials and in particular semiconductors (Feldman and Mayer 1986, Vickerman et al. 1989). Its strengths include relatively good depth resolution combined with very high sensitivity and the ability to profile all elements simultaneously. It has been much less widely used for polymers, even though with some care all these advantages can apply to the polymer case too. 

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To summarize this section, the electrochemical hydrogenation experiments performed to date have yielded substantial penetration of low levels of hydrogen, but show promise for practical utilization despite temperature limitations and complications such as material removal. As with plasma and ion beam methods, the surface of this subject has barely been scratched. 

Cr-ion-doped titania loaded MCM-41 (Ti02/Cr-MCM-41) has exhibited reasonable photocat-alytic activity with visible light for aqueous formic acid conversion [165], Also, Cr ion doping by ion beam methods has been used with some success [166-168],... 

Applications of Ion Beam Methods to Characterization of Adhesive Bonding Materials... 

One important influence in the formation of a good adhesive bond is surface or interfacial chemistry. In the broader sense, in which two substances are held together by interfacial forces, adhesion is of importance in many technologies such as in thin films and semiconductors. It is the purpose of this paper to discuss ion beam methods of surface characterization applicable to the broad area of adhesion with emphasis on adhesive bonding. 

Ion Beam Methods to Characterize Adhesive Bonding Materials 123... 

A serious problem encountered in ion beam methods of analysis is that of specimen charging. Impact of energetic positive ions causes development of a positive charge on the surface of an insulator. This effect is especially prevalent in polymers, because they are usually excellent insulators. Table VII lists work functions for some typical polymers. It is questionable whether the term work function should be used for polymers, but the high value of these numbers shows the reason for the charging exhibited by polymers. 

Photon-based imaging techniques provide invaluable information for the examination of works of cultural heritage. Concerning the determination of the composition, methods like X-ray fluorescence or ion beam methods... 

In this review results from two surface science methods are presented. Electron Spectroscopy for Chemical Analysis (ESCA or XPS) is a widely used method for the study of organic and polymeric surfaces, metal corrosion and passivation studies and metallization of polymers (la). However, one major accent of our work has been the development of complementary ion beam methods for polymer surface analysis. Of the techniques deriving from ion beam interactions, Secondary Ion Mass Spectrometry (SIMS), used as a surface analytical method, has many advantages over electron spectroscopies. Such benefits include superior elemental sensitivity with a ppm to ppb detection limit, the ability to detect molecular secondary ions which are directly related to the molecular structure, surface compositional sensitivity due in part to the matrix sensitivity of secondary emission, and mass spectrometric isotopic sensitivity. The major difficulties which limit routine analysis with SIMS include sample damage due to sputtering, a poor understanding of the relationship between matrix dependent secondary emission and molecular surface composition, and difficulty in obtaining reproducible, accurate quantitative molecular information. Thus, we have worked to overcome the limitations for quantitation, and the present work will report the results of these studies. 

Electron Beam Deoositlon- this technique uses an electron beam instead of an ion beam. In this respect, it is not as versatile as the ion-beam method or other methods used to manufacture thin films. 

The radiative lifetime of the A2A state of CH has been measured as 460 70 ns, using a molecular ion beam method.3... 

X-ray emission (PIXE), heavy ion-induced X-ray emission (HIXE), particle-induced y-ray emission (PIGE), Rutherford backscattering spectrometry (RBS), and elastic recoil detection analysis (ERDA). These methods are also multielemental and nondestructive. In general, when ion beam methods are used it should be kept in mind that sulfur-containing matter may be lost during the irradiation, and therefore sufficiently low beam currents should be employed. Also, sample homogeneity is vital since the volume probed by the ions is rather small. 

FIGURE 1 Atomic density versus atomic fraction of hydrogen for solid carbons and hydrocarbons, after Angus and dayman [10]. a-C H points are full circles and triangles. Amorphous carbon refers to evaporated C, while a-C is deposited by sputtering or ion beam methods. 

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