Spectroscopic studies of carbon-13 synthetic diamond

Abstract

Vibrational absorption spectra in the infrared, and vibronic absorption and luminescence bands in the visible and ultraviolet spectral regions have been studied for synthetic diamonds grown using 99% ¹³C. This is the first such study of any semiconductor for which the isotope of the host material has been totally changed. As expected, vibrational frequencies involving only the motion of carbon atoms are changed in the approximate ratio (12/13)¹2/, whereas those involving carbon and nitrogen are changed according to the square root of the ratio of the reduced masses. The frequency changes observed are consistent with the models proposed recently for the defects responsible for the vibrational absorption lines observed in the infrared spectral region. Furthermore the measurements have allowed the authors unambiguously to identify the 237 meV localised mode in the 5RL band (zero-phonon line at 4.582 eV) of electron-irradiated diamond with the vibration of a carbon atom.