The formation of boron nitride on Fe37Ni alloy

Formation of monolayer and few-layer hexagonal boron nitride nanosheets via surface segregation

“…2 BN nanosheets have been fabricated by mechanical exfoliation, 3,4 liquid phase sonication, [5][6][7][8][9][10] and chemical vapor deposition on various metal substrates. [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] Surface segregation by heat treatment of doped bulk samples to synthesize graphene [27][28][29] and h-BN [30][31][32][33][34][35][36] dates back several decades, and now carbon segregation has become one of the most important approaches for producing extended single-layer graphene. 37 Previously, BN thin films have been synthesized via surface segregation, that is, vacuum thermal treatment of iron-chromium-nickel (Fe-Cr-Ni) alloys doped with boron (B) and nitrogen (N).…”

“…33 As characterized by Auger electron spectroscopy (AES) and electron diffraction, the synthesized BN films had a hexagonal structure with a preferred orientation, and they tended to cover a substrate surface with their (001) basal plane. [32][33][34][35][36] However, few high-resolution electron images of such synthesized h-BN films have been reported. 33 Furthermore, the phenomenon involved in boron and nitrogen segregation is not so clear.…”

“…33 Furthermore, the phenomenon involved in boron and nitrogen segregation is not so clear. 32,[34][35][36] Some reports showed that nitrogen segregation precedes boron segregation, that is, nitrogen is segregated first and traps boron to form epitaxial h-BN films, 32,34 whereas others showed that nitrogen and boron precipitate together on the surface and then epitaxially form h-BN films or that boron and nitrogen precipitate directly as epitaxial h-BN films. 36 Previous work was focused on the growth of thick h-BN films for an inert ultrahigh vacuum application.…”

“…32,[34][35][36] Some reports showed that nitrogen segregation precedes boron segregation, that is, nitrogen is segregated first and traps boron to form epitaxial h-BN films, 32,34 whereas others showed that nitrogen and boron precipitate together on the surface and then epitaxially form h-BN films or that boron and nitrogen precipitate directly as epitaxial h-BN films. 36 Previous work was focused on the growth of thick h-BN films for an inert ultrahigh vacuum application. In the present paper, we report formation of monolayer and few-layer h-BN nanosheets by segregation of boron and nitrogen atoms from a bulk Fe-Cr-Ni alloy doped with B and N. Our high-resolution electron microscope images show that triangular h-BN nanosheets can be formed in a layer-by-layer manner, and the growth is independent of the crystallographic orientation of the polycrystalline Fe-Cr-Ni alloy.…”

Selective Oxidation of a CMnSi Steel during Heating to 1000 °C: Reversible SiO2 Oxidation

“…Epitaxial precipitation of hexagonal boron nitride (h-BN) on austenite, with the c-axis oriented along the (111) c surface normal, has been reported. [32][33][34] The atomic spacing of the basal plane of h-BN and the (111) plane of austenitic iron being similar [32] makes this coherent precipitation possible and facilitates the nucleation of BN at the surface. Consequently, the BN precipitation is favored by the austenitic crystal structure.…”