External reflectance IR spectra

Thin layers (100-1000 A) of polyimide on the substrate were prepared for external reflectance IR spectra and to measure the average depth of modification, which will be discussed in detail. Figure 2 displays the ER IR spectra of the 870-A-thick polyimide and the modified samples in the range of 1900-1300 cm-1 which provide the most useful information for this re-... 

Figure 2. External reflectance IR spectra (a) PMDA-ODA polyimide, (b) potassium polyamate and (c) polyamic acid. The starting polyimide is 870 A thick and the whole layer is modified. The IR incidence angle is 37° from the sample surface.

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