Beyond‑carbon-solvency effects of catalytic metal Ni on diamond growth

Importance of Interfacial Structures in the Catalytic Effect of Transition Metals on Diamond Growth

“…Next, we investigated structural changes induced by the adsorption of M atoms on C(111). Our previous studies 30,31 Figure 3a shows the C2−C3 bond length in 1 × 1 M/ C(111). Moving from left to right in each row of the periodic table, the length decreases and then increases.…”

“…Next, we investigated structural changes induced by the adsorption of M atoms on C(111). Our previous studies , demonstrated that surface Ni adsorption on C(111) favors a diamond bulk-like 1 × 1 interface structure. In this 1 × 1 Ni/C(111) structure, compared to the clean 1 × 1 C(111), the C1–C2 bond is elongated, the C2–C3 bond is shortened, and ∠(C1–C2–C3) has a value (107.7°) close to that of bulk diamond (109.5°).…”

“…More detailed experimental results for these four catalysts showed that Mn, Fe, Co, and Ni have diamond growth temperatures that decrease in that order, despite their similar T m ; ,, interestingly, according to our calculations, they have M–C cleavage energies that also decrease in this order (Figure a). In our previous study, we suggested that surfactant-mediated growth − occurs in the Ni/C(111) system, in which Ni atoms exchange their positions with incoming C atoms for continuous diamond growth, maintaining the 1 × 1 M/C(111) structure. In this process, an M–C bond must be cleaved and a C–C bond is formed.…”

“…In the present work, we studied the catalytic effect of transition metals by carrying out ab initio total energy and electronic structure calculations of transition-metal (M)/ C(111) based on the density functional theory (DFT), 32,33 which extends our earlier work 30,31 to other transition metals. We examined energetics, structural and electronic properties, and metal carbide formation of M on C(111) and obtained characteristic features that are very important for understanding the microscopic mechanism by which transition metals catalyze diamond growth.…”

“…In the context of thin-film growth, many studies have been conducted on surface elements that remove the π-bonds of Pandey chains on C(111) through surface reactions. − Recently, we theoretically investigated the microscopic role of a Ni metal catalyst on C(111) through ab initio electronic and vibrational calculations. , The results showed that the addition of Ni induces the formation of a thermodynamically stable Ni–C interface with an sp 3 -like 1 × 1 diamond bulk-like structure, which is more favorable for diamond growth than an sp 2 -like 2 × 1 Pandey chain structure. This structural change is well represented by the interfacial energy difference between the 1 × 1 and 2 × 1 models.…”