Solid-State Absorption Spectra of Mg and MgO

Linear absorption coefficients have been determined for Mg and MgO for wavelengths from 80A to 350A. The results for Mg have indicated values range from 1.8×${10}^4$ to 12×${10}^4$ ${\mathrm{cm}}^{-1\mathrm{}}$. These values are in reasonable agreement with those extrapolated from the region of the $K$ absorption edge. Surface effects were eliminated by plotting transmission against foil thickness. MgO exhibits three absorption bands in this spectral region. These bands have been tentatively identified and discussed in relation to earlier emission data of O'Bryan and Skinner. A gap of about 4 ev is found to exist between the top filled level and the proposed conduction band.