Ar* ions

Resonance Raman reflection spectroscopy of monolayers is possible, as illustrated in Fig. IV-14 for cetyl orange [157]. The polarized spectra obtained with an Ar ion laser allowed estimates of orientational changes in the cetyl orange molecules with a. 

Polymers. Ion implantation of polymers has resulted in substantial increases of electrical conductivity (140), surface hardness (141), and surface texturing (142). A four to five order of magnitude increase in the conductivity of polymers after implantation with 2 MeV Ar ions at dose levels ranging from 10 -10 ions/cm has been observed (140). The hardness of polycarbonate was increased to that of steel (141) when using 1 MeV Ar at dose levels between 10 -10 ions/cm. Conductivity, oxidation, and chemical resistance were also improved. Improvements in the adhesion of metallizations to Kapton and Teflon after implantation with argon has been noted (142). 

New impetus was given to photomedicine by development of lasers that are compatible with the clinical environment. These include HeNe, Ar ion, mby, and tunable dye lasers operating in the continuous wave (cw) mode. Prior to the advent of lasers in medicine, only the treatment of newborn jaundice, and the appHcation of long wavelength uv irradiation in conjunction with adininistration (or topical appHcation) of psoralen class sensitizers to treatment of skin diseases (86), principally psoriasis, were clinically important phototherapies. 

Figure 1 Schematic of DC glow-discharge atomization and ionization processes. The sample is the cathode for a DC discharge in 1 Torr Ar. Ions accelerated across the cathode dark space onto the sample sputter surface atoms into the plasma (a). Atoms are ionized in collisions with metastable plasma atoms and with energetic plasma electrons. Atoms sputtered from the sample (cathode) diffuse through the plasma (b). Atoms ionized in the region of the cell exit aperture and passing through are taken into the mass spectrometer for analysis. The largest fraction condenses on the discharge cell (anode) wall.

Electrically insulating materials can be analyzed in HF-plasma SNMS by applying a square-wave HF in the 100 kHz range to the sample (Fig. 3.34). Dielectric charge transfer at the start of a period shifts the surface potential to the amplitude Uhfm applied. Ar" ions are attracted from the plasma and sputter the surface until the end of At . The potential increase AU = 1-100 V caused by their charge is then converted to a positive absolute AU which is reduced to less than 1 V within <0.1 ps by the... 

Fig. 2. Raman spectra (T = 300 K) from various sp carbons using Ar-ion laser excitation (a) highly ordered pyrolytic graphite (HOPG), (b) boron-doped pyrolytic graphite (BHOPG), (c) carbon nanoparticles (dia. 20 nm) derived from the pyrolysis of benzene and graphitized at 2820°C, (d) as-synthesized carbon nanoparticles ( 850°C), (e) glassy carbon (after ref. [24]).

Figure 8. The intensity ratio ArH+/ArD+ as a function of the kinetic energy of the incident Ar + ion (8)...

Fig. 31 Evolution of the Raman spectra of a high-pressure and photo-induced sample of Se while decreasing the pressure at ca. 300 K [109]. The spectrum at 3.9 GPa shows the onset of the transformation S6 p-S. The asterisks indicate the Raman signals typical for p-S whereas the peaks of two stretching vibrations of p-S coincide with those of Se at about 458 cm and 471 cm (not indicated by asterisks). The Raman spectrum of the sample recovered at ambient pressure (0 GPa) is evidently a superposition of the spectra of a-Sg and polymeric sulfur, Sj, arrows indicate plasma lines of the Ar ion laser at 515 nm, which have been used for calibration). For Raman spectra under increasing pressure, see Fig. 23 in [1] and references cited therein...

The PTFE/Si3N4 multilayers were prepared by Ar+ ion beam alternatively sputtering pure PTFE and Si3N4 ceramic target in a polyfunctional beam assisted deposition system. Si (100) wafer is the substrate. The mutlilayer film has eleven layers with alternatively PTFE and Si3N4 layers, the inmost and... 

Some results from this study of TIO2 surfaces were In good agreement with previous reports. For example, the C(372) peak could be removed by heating above 875K (20,21,23) Ar Ion bombard-... 

The SIMS system is mounted on a UHV spectrometer which also has XPS, UPS, LEED and thermal desorption capabilities ( ). Heating is achieved by electron bombardment from a filament mounted on the manipulator behind the sample. Cooling is achieved by circulating liquid N2 or He. Temperatures of 25K can be reached. The samples used, Ni(lOO), Cu(17%) Ni(83%) (100) and (111) and Ag(lll) were oriented within 1 and cleaned in situ by standard heating and Ar ion sputtering procedures. 

Figure 8. Valence band XPS (a) and UPS (b) spectra of silver islands on native oxide covered Si(l 0 0) during bombardment with 1 keV Ar" ions. Substrate related contributions are removed. Numbers at each spectra stand for the Ag/Si ratio determined from the appropriate XPS core level spectra. The uppermost curve is the spectrum of polycrystalline bulk Ag. (Reprinted from Ref [146], 1998, with permission from Elsevier.)...

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