Growth-sector dependence of fine structure in the first-order Raman diamond line from large isolated chemical-vapor-deposited diamond crystals

Abstract

The growth-sector dependence of fine structure in the first-order Raman diamond line is investigated for the first time in high resolution spectra taken from large isolated diamond single crystals grown using microwave plasma chemical vapor deposition on tungsten wire tips. The volumes of crystal beneath the (100) and (111) surfaces of these crystals were sampled using a high resolution Raman microprobe from which the line shape of the 1332 cm−1 diamond line was found to be distinctly different. A splitting of the diamond line into two components of up to 7 cm−1 was observed for (100) growth sectors. This splitting may be caused by the buildup of directional strain fields caused by the different fundamental growth processes occurring on the (100) and (111) growth surfaces. An additional third peak near 1326 cm−1 was only observed in (111) growth sectors and may be attributable to the presence of stacking faults.