K-emission Spectra Research Articles

On the emission spectra of some oxides and pure elements in the soft X-ray region

The K-emission spectra of Be and B and the L-emission spectra of Al and Si of the pure elements and their oxides were investigated. Use was made of a vacuum spectrograph with concave grating in tangential incidence. The grating has 2 meter radius and 576 lines to the mm. In agreement with other investigators for metallic Be and Al a broad line with a sharp edge on the short wave-length side was found. This is typical for a metallic conductor. The same was found with a pure boron sample, which proves that this element has to be regarded as a conductor. The emission line of Si looks more like that of a semi-conductor or insulator. The oxides of these elements, however, give broad emission lines which are typical for totally filled valency-bands. For B and Si the short wavelength side of these lines (or group of lines) has a higher frequency for the oxides than for the metals. In the case of Be and Al the reverse is true. It is reasonable to assume that these lines consists of two broad lines which partly overlap. In the case of BeO, besides, a new broad line of smaller frequency has been found, which may be regarded as K → L transition. In the case of B 2O 3 a boron-line is found, which may be interpreted in the same sense.