Bibliographic Details
| Title: |
Topological Constraint Theory Analysis of Rigidity Transition in Highly Coordinate Amorphous Hydrogenated Boron Carbide |
| Authors: |
Bradley J. Nordell, Thuong D. Nguyen, Anthony N. Caruso, William A. Lanford, Patrick Henry, Han Li, Liza L. Ross, Sean W. King, Michelle M. Paquette |
| Source: |
Frontiers in Materials, Vol 6 (2019) |
| Publisher Information: |
Frontiers Media S.A., 2019. |
| Publication Year: |
2019 |
| Collection: |
LCC:Technology |
| Subject Terms: |
boron carbide, amorphous hydrogenated boron carbide, amorphous solids, topological constraint theory, rigidity theory, Technology |
| More Details: |
Topological constraint theory (TCT) has revealed itself to be a powerful tool in interpreting the behaviors of amorphous solids. The theory predicts a transition between a “rigid” overconstrained network and a “floppy” underconstrained network as a function of connectivity or average coordination number, 〈r〉. The predicted results have been shown experimentally for various glassy materials, the majority of these being based on 4-fold-coordinate networks such as chalcogenide and oxide glasses. Here, we demonstrate the broader applicability of topological constraint theory to uniquely coordinated amorphous hydrogenated boron carbide (a-BC:H), based on 6-fold-coordinate boron atoms arranged into partially hydrogenated interconnected 12-vertex icosahedra. We have produced a substantial set of plasma-enhanced chemical vapor deposited a-BC:H films with a large range of densities and network coordination, and demonstrate a clear threshold in Young's modulus as a function of 〈r〉, ascribed to a rigidity transition. We investigate constraint counting strategies in this material and show that by treating icosahedra as “superatoms,” a rigidity transition is observed within the range of the theoretically predicted 〈r〉c value of 2.4 for covalent solids with bond-stretching and bond-bending forces. This experimental data set for a-BC:H is unique in that it represents a uniform change in connectivity with 〈r〉 and demonstrates a distinct rigidity transition with data points both above and below the transition threshold. Finally, we discuss how TCT can be applied to explain and optimize mechanical and dielectric properties in a-BC:H and related materials in the context of microelectronics applications. |
| Document Type: |
article |
| File Description: |
electronic resource |
| Language: |
English |
| ISSN: |
2296-8016 |
| Relation: |
https://www.frontiersin.org/article/10.3389/fmats.2019.00264/full; https://doaj.org/toc/2296-8016 |
| DOI: |
10.3389/fmats.2019.00264 |
| Access URL: |
https://doaj.org/article/ad3c215889544718b857dbb899300da6 |
| Accession Number: |
edsdoj.3c215889544718b857dbb899300da6 |
| Database: |
Directory of Open Access Journals |
