Infra-red absorption of gallium phosphide containing boron

Absorption due to boron vibrational modes in GaP has been measured. At 20 °K gap modes of 11B and 10B occur at 284·2 and 293·8 cm-1, local modes occur at 571·0 and 593·6 cm-1 and local +gap modes occur at 849·0 and 882·4 cm-1. An approximate calculation of the boron vibrational mode frequencies gives reasonable agreement with experiment.