Effect of annealing on the spin density of dangling bonds and the structures of amorphous germanium

Electron paramagnetic resonance was used to study the dependence of the volume spin density of dangling bonds ina-Ge films produced by cathode sputtering in argon on annealing temperature. The structure of the films is determined by x-ray diffraction analysis. Two EPR lines with g=2.019 and g=2.003 are observed whose intensities change nonmonotonically with annealing temperature. The g=2.019 line is characteristic only of the amorphous state of germanium, while the g=2.003 line persists even after crystallization of the films. When the results are compared with structure data, the conclusion may be drawn that the observed lines in the EPR spectrum are related to the dangling bonds in the peripheral regions of two types of clusters. The g=2.003 line is due to dangling bonds in the peripheral region of clusters with the usual cubic packing of atoms, and the g=2.019 line is due to clusters of the hexagonal type, which is not characteristic of the normal structure of crystalline germanium.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 7, pp. 51–57, July, 1989.