Positron-reemission-microscope study of positron implantation and diffusion

The results of high-resolution laterally resolved measurements of positron implantation and diffusion are presented. High-magnification (4400x), transmission-mode positron-reemission-microscopic images of a compound sample, which inhibited positron implantation in a well-defined region, were taken for positron implantation energies ranging from 3 to 9 keV. The lateral spreading was determined by examining the positron emission intensity across the boundary of the implantation inhibiting region. The lateral spreading is typically observed to be at least 500 A larger than the 1850 A value calculated using standard implantation and diffusion models. Possible explanations for the discrepancy are discussed