The neutral vacancy in diamond

Abstract

The GR 1 radiation damage centre in diamond has been studied by means of optical absorption and uniaxial stress. Two zero phonon lines at 1.665 and 1.673 eV have been associated with the defect, and an energy level scheme is proposed to explain the thermal behaviour of the lines. The energy level diagram facilitates the interpretation of the uniaxial stress data, and it is concluded that the defect possesses tetrahedral symmetry. Comparison of the energy level scheme derived experimentally with theoretical treatments of intrinsic defects in diamonds suggests that the GR 1 centre is probably the neutral vacancy.