Mg‐Facilitated Growth of Cubic Boron Nitride by Ion Beam‐Assisted Molecular Beam Epitaxy

Abstract

Trace amounts of Mg deposited on a diamond (100) substrate surface facilitate the growth of cubic boron nitride (c‐BN) by ion beam‐assisted molecular beam epitaxy. Fourier transform infrared spectroscopy indicates that films grown with Mg are cubic, while those without Mg are either hexagonal BN or lacking measurable cubic or hexagonal signatures. Initiating the growth with 0.005 monolayer equivalent of Mg is sufficient to yield epitaxial films with >99% c‐BN. Reflection high energy electron diffraction, electron energy loss spectroscopy, and X‐Ray photoelectron spectroscopy indicate the surface of the film to be sp2‐bonded BN, consistent with the results of other groups. High‐resolution scanning transmission electron microscopy reveals c‐BN with a high density of stacking faults and twinning. A model is proposed by which Mg locally diminishes the energy barrier to dissociation of the as‐deposited sp2‐bonded BN, facilitating the nucleation of c‐BN.

Hydrogen-driven boron nitride phase differentiation during the epitaxial nucleation on the diamond (001) surface

“…The successful synthesis of single-crystal cBN was demonstrated through several methods using diamond as a convenient heteroepitaxial substrate. 7,[10][11][12][13][14][15][16] Molecular beam epitaxy (MBE) and physical vapor deposition (PVD) approach in the absence of hydrogen typically produce aBN followed by cBN formation. Commonly employed etching of aBN through ion bombardment leaves behind a pure cBN phase, which, unfortunately, is plagued by poor crystallinity, high defect density, and internal stress caused by high-energy ions.…”

The Stability Prediction and Epitaxial Growth of Boron Nitride Nanodots on Different Substrates

“…Various techniques have been employed for the fabrication of BN, including physical vapor deposition (PVD) [ 7 , 8 , 9 , 10 ], chemical vapor deposition (CVD) [ 11 , 12 , 13 , 14 ], and molecular beam epitaxy (MBE) [ 15 , 16 , 17 , 18 ], to grow both c-BN and h-BN. Among these methods, plasma-assisted molecular beam epitaxy (PA-MBE) allows for precise growth control, resulting in high-quality epitaxy at lower growth temperatures [ 19 ].…”

Phase Stability of Hexagonal/Cubic Boron Nitride Nanocomposites

“…As shown, in XRD (Figure a) both show the characteristic diffraction peaks, with the most intense ones for (002) of h-BN and (111) of c-BN, the most stable structure of respective phases, signifying that most of the grains are oriented along these directions. XPS shows the characteristic B–N peaks (at B 1s and N 1s core) for both cases; however, an additional π-plasmon peak appears for h-BN (at ∼9 eV from the B–N peak), but not for the case of c-BN (Figure b). − We also performed XPS valence band spectroscopy (VBS) of h-BN and c-BN (supplementary Figure S1). The VBS of the c-BN exhibits a similar shape as observed for h-BN, with a moderate shift of valence band maxima (VBM) toward lower binding energy from the Fermi level ( E F ). , FESEM shows 2D sheet-like features for h-BN (sheets of few μm), whereas 3D islands for c-BN (grain size <1 μm) (Figure c).…”