Interaction of energetic ions with inhomogeneous solids

We use quantitative chemical mapping and statistical analysis to explore the microscopic consequences of the passage of energetic ions through AlAs/GaAs multilayers. We thus quantitatively characterize and microscopically identify the damage cascades produced by individual 320-keV ${\mathrm{Ga}}^{+}$ ions. Our results reveal a strong drift of the damage in the applied electric field, indicating the effects to be charged. We exploit this effect to show that the defects produced by the passage of energetic ions may be microscopically steered in a solid.