  In-depth analysis of pulsed laser atom probe tomography (APT) data on the
field evaporation of the III V semiconductor material GaSb reveals strong
variations in charge states, relative abundances of different cluster ions,
multiplicity of detector events and spatial correlation of evaporation events,
as a function of the effective electric field at the specimen surface. These
variations are discussed in comparison with the behaviour of two different
metallic specimen materials, an Al-6XXX series alloy and pure W, studied under
closely related experimental conditions in the same atom probe instrument. It
is proposed that the complex behaviour of GaSb originates from a combination of
spatially correlated evaporation events and the subsequent field induced
dissociation of cluster ions, the latter contributing to inaccuracies in the
overall atom probe composition determination for this material.
