Local-vibrational-mode absorption of two O-H centres in GaP

In LEC-grown GaP, two vibrational lines at 3250.9 cm(-1) and 3106.0 cm(-1) are measured and assigned to the stretching modes of two different O-H cent res. In GaP containing both hydrogen and deuterium, two additional lines ap pear, both shifted to lower energies by the same factor r = 1.346. This res ult shows that both O-H centres contain only one hydrogen atom. The O-D lin e at 2415 cm(-1) is split into two lines. This splitting possibly indicates a further example for resonant interaction of local modes with extended on es. The comparison with GaAs suggests the assignment of two lines to the an alogous O-H centres in GaAs.