Estimating the lower-limit of fracture toughness from ideal-strength calculations

Borgsmiller, Leah; Agne, Matthias T.; Male, James P.; Anand, Shashwat; Li, Guodong; Snyder, G. Jeffrey

doi:10.1039/d1mh01831k

Cited by 5 publications

(1 citation statement)

References 78 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Because crack propagation in brittle materials is caused by the breaking of a single bond at the crack tip 48 and the stress on the breaking of a bond at the crack tip corresponds to the ideal tensile strength 10 , the fracture toughness is considered to be related to the ideal tensile strength, which in turn corresponds to the bond strength. In fact, some studies have attempted to estimate fracture toughness from the stress–strain relationship of ideal strength calculations 49 , 50 . Based on the relationship between ideal tensile strength and fracture toughness, the increase in ideal tensile strength of hole doped Si is qualitatively consistent with the increase in fracture toughness of hole doped Si in the experiment.…”

Section: Resultsmentioning

confidence: 99%

Electronic strengthening mechanism of covalent Si via excess electron/hole doping

Noda,

Sakaguchi,

Fujita

et al. 2023

Sci Rep

View full text Add to dashboard Cite

Brittle fracture of a covalent material is ultimately governed by the strength of the electronic bonds. Recently, attempts have been made to alter the mechanical properties including fracture strength by excess electron/hole doping. However, the underlying mechanics/mechanism of how these doped electrons/holes interact with the bond and changes its strength is yet to be revealed. Here, we perform first-principles density-functional theory calculations to clarify the effect of excess electrons/holes on the bonding strength of covalent Si. We demonstrate that the bond strength of Si decreases or increases monotonically in correspondence with the doping concentration. Surprisingly, change to the extent of 30–40% at the maximum feasible doping concentration could be observed. Furthermore, we demonstrated that the change in the covalent bond strength is determined by the bonding/antibonding state of the doped excess electrons/holes. In summary, this work explains the electronic strengthening mechanism of covalent Si from a quantum mechanical point of view and provides valuable insights into the electronic-level design of strength in covalent materials.

show abstract