Highly delocalised molecular orbitals in boron-, carbon- and nitrogen-based linear chains: a DFT study

Segregation of boron, carbon and nitrogen to grain boundaries in a nickel based model alloy has been investigated using atom probe field ion microscopy (APFIM). The material corresponds to a commercial alloy (Inconel 600), but contains lower levels of alloy additives and impurities. The major composition was Ni-16Cr-10Fe (wt.%). The alloy was solution annealed at 950°C for 10 min, which resulted in a grain size of 20 μ. Subsequently heat treatments for 1 h at temperatures of 550°C, 600°C and 700°C were applied. TEM investigation showed that the heat treatment at 700°C resulted in precipitation of intergranular chromium-rich carbides. The other temperatures were obviously too low and the aging times too short to cause precipitation, since carbides were not observed in the materials heat treated at 550°C and 600°C.As the grain size was about 100 times larger than the accessible depth of APFIM analysis (≃200 nm), much care had to be taken in preparing samples containing a grain boundary close to the tip apex.

Download Full-text

The impregnation of oxygen, sulfur, boron, carbon, and nitrogen into the surface of high-speed steel cutters in a gaseous medium

Journal of Heat Treating ◽

10.1007/bf02833150 ◽

1983 ◽

Vol 3 (1) ◽

pp. 16-22 ◽

Cited By ~ 2

Author(s):

Z. -M. Guan ◽

G. -X. Liu ◽

H. -J. Xu ◽

S. -R. Peng

Keyword(s):

High Speed ◽

Gaseous Medium ◽

High Speed Steel ◽

Carbon And Nitrogen ◽

Boron Carbon

Download Full-text

ELNES for boron, carbon, and nitrogen K-edges with different chemical environments in layered materials studied by density functional theory

Ultramicroscopy ◽

10.1016/j.ultramic.2011.10.011 ◽

2012 ◽

Vol 112 (1) ◽

pp. 61-68 ◽

Cited By ~ 14

Author(s):

Jingying Lu ◽

Shang-Peng Gao ◽

Jun Yuan

Keyword(s):

Density Functional Theory ◽

Density Functional ◽

Layered Materials ◽

Functional Theory ◽

Carbon And Nitrogen ◽

Boron Carbon

Download Full-text

Activation of Acetylene by Coordination to Bis-Triphenylphosphine Complex of Pt(0): DFT Study

Chemistry Journal of Moldova ◽

10.19261/cjm.2009.04(1).01 ◽

2009 ◽

Vol 4 (1) ◽

pp. 123-128

Author(s):

N. N. Gorinchoy ◽

B. Dobrova ◽

M. Yu. Gorbachev ◽

G. Munteanu ◽

I. Ya. Ogurtsov

Keyword(s):

Dft Calculations ◽

Detailed Analysis ◽

Theoretical Study ◽

Molecular Orbitals ◽

Dft Study ◽

Electronic Density ◽

Acetylene Molecule ◽

Important Conclusion ◽

Triphenylphosphine Complex ◽

Back Donation

The present work is devoted to the theoretical study of the activation of the acetylene molecule coordinated in the [Pt(PPh3)2C2H2] complex. By means of DFT calculations it is shown that the geometrical and electronic characteristics of the C2H2 are essentially changed due to its coordination. The subsequent detailed analysis of the molecular orbitals (MO) of the active valence zone of this complex allows one to make important conclusion that this activation is being realized mainly due to the orbital back donation of 5d-electronic density from one of the occupied MOs of the complex [Pt(PPh3)2] to the unoccupied antibonding π*-MO of C2H2.

Download Full-text

STRUCTURAL AND ELECTRONIC PROPERTIES OF BCN NANOFLAKES VIA GRAPH THEORY

10.12783/asc36/35864 ◽

2021 ◽

Author(s):

SHUSIL BHUSAL ◽

JONGHOON LEE ◽

AJIT K. ROY

Keyword(s):

Graph Theory ◽

Density Functional ◽

Hexagonal Boron Nitride ◽

Hexagonal Lattice ◽

Stoichiometric Ratio ◽

Carbon And Nitrogen ◽

Novel Materials ◽

Structural And Electronic Properties ◽

Boron Carbon Nitride ◽

Boron Carbon

Boron-carbon-nitride (BCN), a ternary system, enables us to compose a wide variety of novel materials due to their unique mechanical, thermal, and electrical properties. We study two-dimensional structures called nanoflakes made of boron, carbon, and nitrogen atoms arranged in hexagonal lattice structures. The physical properties of these nanostructures, in general, are functions of the overall shape, stoichiometric ratio of boron carbon and nitrogen atoms, and their distribution. In this study, we utilize graph theory to randomly generate these structures, forming three different phases: hexagonal graphene, hexagonal boron nitride, and hexagonal BCN in various proportions. We perform density functional theory (DFT) simulations to obtain the optimized nanoflake structures and analyze the electronic structure. Our results have important implications for future studies of novel materials based on BCN nanoflakes and their experimental realizations.

Download Full-text