Kβ2 X-ray emission bands of Ga and As and their compounds

Abstract

Ga and As Kβ 2 emission bands of the compounds under study consist of a more or less pronounced Kβ 2 main band, a short-wavelength side band which according to calculations by the ‘sudden approximation’ method may be essentially assigned to a KM IV,V → M IV,V N II,III satellite, and long-wavelength 3 d → 1 s bands. Compounds such as Ga 2(SO 4) 3, Ga(NO 3) 3, Ga 2O 3, NaH 2AsO 4, K 3AsO 4, and As 2O 3 also show long-wavelength side-maxima at a distance of about 12 and 15 eV, respectively, from the main band, which are due to electron transitions from bands or levels with a preponderant 0 2 s character. The Kβ 2 main band of A III B V compounds is less pronounced owing to the widths of the K levels and to instrumental distortions. The distance between the maxima of the state density of the upper valence bands can be recognized only by a shoulder or asymmetry of the band at the long-wavelength side. By calculation of the Ga and As Kβ 2 bands in GaAs with a pseudopotential kp band structure method, and allowing for the influence of both the transition probability and instrumental distortion excellent agreement with experiment is obtained.