Does Twinning Impact Structure/Property Relationships in Diamond Nanoparticles?

Abstract

Although the majority of computational predictions of the properties of diamond nanoparticles (nanodiamonds) are based on sets of exclusively single-crystal structures, most experimental observations contain twins. The influence of twins is difficult to characterize computationally since they are metastable and their relative stability will depend on the thermochemical conditions. The properties of entire samples of nanodiamonds will also depend on how many twins there actually are. In this study, we have used a combination of electronic structure simulations, ab initio thermodynamics, and a simple statistical method called ensemble filtering to investigate the probability of twinning in nanodiamond and their impact on charge transfer properties such as the ionization potential, the electron affinity, and the electronic band gap. We find that, provided some degree of control can be exercised over the surfaces, increasing the number of twinned particles in samples could shift the selectivity of the electron affinity and the band gap and could greatly improve the quality of samples by decreasing the bandwidth, improving the sensitivity and specificity.

Inverse Design of Nanoparticles Using Multi‐Target Machine Learning

“…This included the formation energy (Formation_E) and thermodynamic probability of observation (Probability) originally calculated using a Boltzmann distribution and the free energy different at 300 K at atmospheric pressure. [20] The electron change transfer properties included the ionization potential (IP), the electron affinity (EA), the electronic band gap (EG), the electronegativity (EN), or the energy the Fermi level (EF), all measured in eV. Labeling was not conducted as part of this study, and information on how the labeling was conducted can be obtained from references listed on the data repository.…”

Quantum Point Defects for Solid‐State Laser Refrigeration

“…Additionally, the extreme non‐equilibrium conditions of the detonation process can lead to the formation of twinning planes that may also alter the optoeletronic properties of detonation nanodiamond materials. [ 169 ]…”

“…[ 188 ] Bulk high‐pressure high‐temperature (HPHT) diamonds may also be milled into smaller, nanoscale grain sizes following implantation and thermal annealing. [ 189 ] However, the milling process has been observed to introduce a number of defects within the final nanodimaond material including twinning planes, [ 169 ] and surface states. [ 190–193 ] As discussed above, the quality of diamond surfaces can be improved through the use of oxidizing acids to create a large fraction of surface oxygen termination.…”

“…However, plasma based growth also introduces hydrogen within the diamond crystal lattice, [ 184,185 ] leading the possibility of nonradiative color centers that may also serve as a source of background absorption. [ 186 ] Furthermore, twinning defects [ 187 ] have been observed in diamond materials growth through plasma deposition [ 169 ] and must also be considered when determining potential sources of background absorption.…”

Structural, electronic, and thermodynamic properties of TiO2/organic clusters: performance of DFTB method with different parameter sets

“…[13,[18][19][20] Among the variety of simulation methods, the density functional tight-binding theory (DFTB) is one of the promising alternatives. It provides a very efficient estimation of different properties for many organic, [25][26][27][28] inorganic, [29][30][31][32] and organometallic [33][34][35] species. However, its application to the TiO 2 -based materials, especially in contact with metallic nanoparticles, is still restricted due to the lack of reliable atomic parameters for Ti and other metal atoms.…”