Effects of hydrogen impurity on diamond crystal growth process

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

“…However, This result contradicts the data published in the article of Hu et al, [21] which show that added phosphorus pushes the V-shaped region of diamond synthesis towards higher pressures and temperatures. In our experiment, it was found that the catalytic activity of composite catalyst FeNiMnCo with a certain proportion (Fe 64 Ni 36 ： Ni 70 Mn 25 Co 5 =1:1, Namely, Fe 32 Ni 53 Mn 12.5 Co 2.5 ) of both alloys is better than that of FeNi or NiMnCo for synthesizing diamond [6] . Therefore, when phosphorus is added in graphite (carbon source) with FeNiMnCo catalyst for synthetic diamond, the temperature interval for the (100) -( 111 wt%, the synthesis diamond crystal is dark color and the surface has many defects, as shown in Fig.…”

“…[1][2][3][4] However, if there are impurities incorporated into diamond lattices, the properties of diamonds will be affected or completely deteriorated. Nitrogen and boron are main impurities in natural diamonds, and other elements can be added in synthetic diamonds [5][6][7][8][9] . In recent years, researchers mainly have focused on diamonds doped with nitrogen, boron, phosphorus and sulfur.…”

Understanding continuous wave laser-induced chemical reactions at micro- and nano-diamond-glass interface under infrared excitation

“…The most prominent diamond reflection, associated with (111) planes, was located at 43°for 2θ, while the other at 75°was associated with (220) diamond planes. Minor peaks observed at 30°to 40°were attributed to nitrogen [23,31] and metals remaining in the structure were residues of the catalysts used in the synthesis [32,33]. Figures 1(d) and (e) display representative x-ray diffraction (XRD) outcomes obtained for nDs.…”

Novel synthesis and properties of hydrogen-free detonation nanodiamond

“…ND surface, which otherwise could link to further carbon atoms. Indeed, there is experimental evidence [43] that such hindering actually occurs: with increasing hydrogen concentration, minimum conditions for diamond synthesis increase steeply, while an excess of TiH 2 suppresses diamond growth altogether. Without this inhibition, HFND particles grow bigger, hence have relatively fewer surface atoms and fewer sites for hydrogen, which in ND is mostly located at the surface (as shown by NMR [27]), although it can also participate in internal defects [44,45].…”