Sputtered absorption spectrum

Cr-doped Ti02 has been widely studied for photoanode application since addition of Cr shifts the optical absorption spectrum towards the visible range, with the caveat that excess chromium doping leads to higher recombination rates. Various synthesis methods have been employed to date. For example Radecka an coworkers used r.f. sputtering to prepare up to 16 at% Cr-doped Ti02 [70]. XRD reveals that at low Cr concentration the... 

Fig. 4. The optical absorption spectrum of Agg" " produced by ion sputtering. The temperature of the cluster ion is estimated to be above 400 K. Squares show experimental data the solid line is for eye-guide. The broad spectral feature is attributed to a surface plasmon resonance, where electrons are excited collectively. (Adapted from Ref. 8.)...

These layers were deposited by magnetron sputtering on A1 substrates maintained at temperatures of 25° and 250°C. The spectrum obtained by IRRAS for the film deposited at 25°C (Fig. 3.68a) shows an intense vlo absorption band at 725 cm . In the spectrum of the film deposited at 250°C, the maximum of this band is shifted to higher frequencies, and its FWHM is smaller than that in the spectrum of the film obtained at 25°C. The resulting spectral dependences of n2(v) and k2 v) for the MgO layers are presented in Fig. 3.68Z . The optical constants of the layer sputtered on the 250°C substrate are close to those of a MgO crystal. The lower frequency and larger bandwidth of the / 2(v) band suggest an amorphous phase in the layer. 

The FT-IRRAS spectrum shown was obtained by ratioing the spectrum taken before the with the one taken after sputtering away all the lubricant. Ratioing spectra taken after sputtering or taken before and after a second sputtering showed no absorption bands due to lubricant or decomposition products. The features marked by arrows are all infrared active vibrational bands of bulk liquid lubricant... 

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