Selective Control of Oxidation Resistance of Diamond by Dopings

Abstract

A method based on the density functional theory calculations is proposed for predicting the influences of dopants on the diamond oxidation, by evaluating the O adsorption energy, chemical bond weakening related to desorption, and probable products. It is proven by verification tests that oxidation resistances of the diamond materials can be indeed selectively controlled (e.g., −36 to 54.3% for diamond films, −36.5 to 45.1% for diamond grits) by adding various doping sources ((CH 3 O) 3 B, Si(OC 2 H 5 ) 4 , N 2 , and CO(NH 2 ) 2 ), attributed to their direct impurity incorporation, or modified gas chemistry. B and Si dopings can improve the oxidation resistance, but the addition of N 2 or urea plays an opposite role. Reactive ion etching and chemomechanical polishing tests are also accomplished, further demonstrating the influences of dopings on oxidation-related processes. This study paves the way for enhancing the efficiencies of the ultraprecision machining and micro−nano machining on the diamonds. Most importantly, the proposed prediction method can be potentially used in similar cases with other dopants and in other materials.

Properties of Electrospun Aligned Poly(lactic acid)/Collagen Fibers with Nanoporous Surface for Peripheral Nerve Tissue Engineering

“…[ 45 ] Moreover, enhanced hydrophilicity due to the addition of COL was more conducive to cell spreading and thus promoted the proliferation. [ 42,55 ]…”

“…In addition to the composition of the material itself, the surface roughness, porosity, pore size, hydrophilic properties of the materials, and other factors also have influences on the cell proliferation. [ 20,53,55,56 ] In general, higher porosity, larger pore size, and enhanced hydrophilicity can promote cell proliferation. [ 53,57,58 ] Compared with PLA/COL‐PA‐3, PLA/COL‐PA‐2 showed higher porosity but smaller pore size (Figure 1H) and poorer hydrophilicity (Figure 2B).…”

Electronic, Tensile, and Sliding Characteristics of the C/Ti Interface: A First-Principles Study

“…At present, first-principles have become an important method to study the surface, interface, and doping properties of diamond (or a-C). − Jia et al calculated the transport properties of Ti on the diamond (100) surface by first-principles. It was discovered that when the content of Ti atoms is low, Ti atoms preferentially adsorb on C–C dimers, but when the content of Ti atoms increases, Ti atoms adsorb in the gap of C–C dimers.…”