Observation of porphyritic texture in hot filament CVD diamond films

The porphyritic texture of diamond films synthesized by hot filament CVD (H FCVD) is reported for the first time. The porphyritic texture has two disti nct crystal habits, where phenocrysts are set in a matrix of fine grains. T he morphology and quality of films were investigated by scanning electron m icroscopy and Raman spectroscopy. A growth model employing secondary nuclea tion and growth illuminates the growth mechanism of this unusual texture. W e also compare the similarity and difference between Wild's and our results on the spherical shape of a multiple faceted particle, which is formed by multiple twinning.