Study on synthesis and electrical properties of slab shape diamond crystals in FeNiMnCo-C-P system under HPHT

This paper reported the synthesis of slab shape diamond crystals with phosphorus doping from FeNiMnCo-C system in cubic anvil high pressure apparatus (SPD-6 × 1200) at 5.6 GPa and 1250-1320 °C. It was attributed to the presence of additive phosphorus that the temperature region of synthetic sheet cubic diamond increases evidently. With the increase of phosphorus content, the surfaces of the slab shape diamond crystals became rough. The results of Raman spectroscopy indicated that the diamonds doped by more phosphorous have more crystal defects and impurities. Furthermore, the electrical properties of the large diamond crystals were tested by a four-point probe and the Hall Effect method. It was shown that the large single crystal samples were n-type semiconductors. This work enriches the application of the slab large diamond crystals.