Mn impurity lattice location in the ferromagnetic zincblende gallium manganese arsenide layer structure

Very weak Bragg reflections have already been used successfully to investigate dopant positions in the structure of the host lattice. The intensity of the x-ray diffracted beam is a function of the structure factor, F, which in turn is modified by the presence of the additional dopant atoms in the lattice. That change can be measured by carefully analysing the integrated intensity of the relevant weak reflections. New materials like low temperature GaMnAs layers are the subject of recent vigorous investigations into their various properties. A theoretical model based on detailed calculations of the structure factor is a way of answering the basic question about the lattice arrangements of the Mn atoms in the host lattice of the GaAs layer. Understanding the structural properties of these materials is essential, and investigations into the local arrangements around the dopant atoms are vital. One can do this through measurements of the quasi-forbidden (very weak) x-ray reflections. Our evaluation clearly indicates the need for the highest possible temperature control and stability of the growth process of such materials.