Auger refers to a process by which electrons are ejected from a sample. The electrons may be ejected by various techniques such as bombarding the sample with x-rays but eventually the "Auger electrons" leave the sample with energies characteristic of the atom from which they originated. The technique thus becomes useful in determining the composition of a given sample. Additionally, Auger analysis yields information about the respective concentrations of the various elements in a sample. Details on Auger spectroscopy can be found on the following web sites:

Queen Mary and Westfield 
Physical Electronics