Fine iron particles formed in a sapphire crystal by the ion implantation technique

The magnetic properties of iron atoms implanted into a sapphire crystal at a dose from 4 X 10(16) to 1 x 10(17) Fe/cm(2) were investigated using conversion electron Mossbauer spectroscopy at low temperature. It was confirmed that the components in the Mossbauer spectra which have been assigned to the Fe4+ state so far by other researchers are caused by fine particles of metallic iron, and about 75% of the implanted iron atoms stabilize in the form of fine particles of alpha iron at high implantation dose. Growth of the fine particles was simulated with a computer, and the expected Mossbauer spectra were calculated considering the influence of the nearest neighbors and next-nearest neighbors on the magnetic hyperfine field of the iron atoms. The simulated spectra agrees well with the experimentally observed spectra on the whole. (C) 1998 American Institute of Physics.