We have observed the local vibrational mode (LVM) infrared absorption
spectra at 77 K from 2 MeV proton-implanted InP crystals doped with di
fferent concentrations of Fe. It is found that the intensity of the LV
M which is created at 2286 cm-1 is dependent on the Fe concentration.
We conclude that this LVM is due to a P-H, Fe(In) complex.