Impurity lattice location in ion-implanted beryllium: Measurements and systematics

Abstract

As part of a program to examine the ion implantation process in metals, the lattice location of 24 elements implanted into beryllium has been studied using the ion-beam channeling technique. A qualitative inspection of the data showed that the major fraction of all implants, except H and He, occupy a highly unique site in the vicinity of either the substitutional, the tetrahedral interstitial, or the octahedral interstitial position in the Be lattice. Quantitative comparisons of the data were made with the results of analytical calculations in the continuum model of the channeling process as well as with the results of a Monte Carlo computer simulation using the binary collision model. Classical metallurgical parameterizations, such as Darken-Gurry plots fail to adequately account for observed impurity site preference. Elemental parameters devised by Miedema have however been successful in relating choice of lattice site to the properties of the impurity relative to those of Be.